Home Ingredients 2'-Fucosyllactose (2'-FL)

2'-Fucosyllactose (2'-FL)

Evidence Level
Limited
8 Clinical Trials
6 Documented Benefits
2/5 Evidence Score

2'-Fucosyllactose (2'-FL) is the most plentiful of the oligosaccharides found in human breast milk. The versions sold in infant formula and adult supplements are made either by chemical synthesis or by fermentation with genetically modified bacteria, and the FDA and EFSA have reviewed it for safety. Gut bacteria such as bifidobacteria can use it, and in placebo-controlled trials it raised bifidobacteria at some doses but not others. A 6-week trial in older adults missed its main immune outcome. In one 12-week trial during a diet and walking program, body weight, body fat and lean mass changed no differently on 2'-FL than on placebo. Trials in people with bowel complaints used a blend of 2'-FL and another milk oligosaccharide, LNnT, and found no symptom difference from placebo. Most adult trials were funded by makers, and high doses can cause gas and loose stools.

Studied Dose Adult trials of 2'-FL alone used 1 or 5 g a day for 6 weeks, 2 g for 4 weeks, 3 g for 12 weeks, 12 g for 8 weeks and 5, 10 or 20 g for 2 weeks. Infant formulas tested 0.2 to 1.0 g per liter.
Active Compound 2'-Fucosyllactose (2'-FL), a three-sugar carbohydrate (trisaccharide) also called 2'-O-fucosyllactose. Commercial 2'-FL is human-identical: it is made by chemical synthesis or by fermentation with genetically modified strains of E. coli or Corynebacterium glutamicum, not extracted from breast milk.

Benefits

Bifidobacteria in the adult gut

In two placebo-controlled trials in healthy adults, 2'-FL alone raised gut Bifidobacterium more than placebo at some doses: 10 g a day but not 5 or 20 g over 2 weeks, and 5 g but not 1 g a day at the midpoint of a 6-week trial. This is a change in a gut bacteria marker, not a measured health outcome, and both trials were funded by makers.

Supported by Trial 1, Trial 2

Body composition during a 12-week diet and exercise program

In a single maker-funded trial in 41 adults with overweight who walked more and cut 300 calories a day, 3 g a day of 2'-FL for 12 weeks did not change body weight, fat mass, body fat percentage, lean mass or waist size compared with placebo, the trial's main measures. Fat mass fell from baseline only in the 2'-FL group, and its bone mineral content fell slightly.

Supported by Trial 3

Immune and inflammation markers

In 89 healthy older adults, 1 or 5 g a day for 6 weeks did not change the main immune outcome, a cytokine response score. In a trial after a course of antibiotics, fasting IL-6 fell more on 12 g a day than on placebo. In formula-fed infants, 2'-FL was linked to lower blood inflammatory markers. None of these trials measured infections in adults.

Supported by Trial 2, Trial 4

Recovery of gut bacteria after a course of antibiotics

In 37 adults with overweight who first took the antibiotic vancomycin for 7 days, 12 g a day of 2'-FL helped gut bacteria move back toward their starting state more than placebo after 2 weeks, but the difference was gone by 8 weeks. A sequencing substudy of 18 participants found no improvement in recovery at 8 weeks.

Supported by Trial 4, Trial 3

Mood ratings in working adults with everyday stress

In a 5-week trial in 92 working adults with mild to moderate anxiety and low mood, mood scores improved within the group taking 2 g of 2'-FL a day, but oligofructose, alone or with 2'-FL, improved several mood measures more than 2'-FL alone. The trial was funded by an oligofructose maker, and mood was a secondary outcome.

Supported by Trial 5, Trial 1

Bowel comfort and bowel habits

No placebo-controlled trial cited here found better bowel function or comfort with 2'-FL. In adults with IBS, a 2'-FL and LNnT blend raised bifidobacteria but symptoms did not differ from placebo, and in stressed working adults 2 g a day of 2'-FL did not change gas, bloating or abdominal pain compared with placebo.

Supported by Trial 1, Trial 6

Mechanism of action

1

Food for bifidobacteria

Human enzymes cannot directly break down milk oligosaccharides such as 2'-FL, but gut bacteria such as Bifidobacterium can use them, and taking 2'-FL raised Bifidobacterium in adult trials. In the older adult trial, people who showed no rise in bifidobacteria were more likely to have none detectable in their gut at the start.

2

Short-chain fatty acids

Fermentation of 2'-FL produces short-chain fatty acids. In a one-day crossover study in men, plasma butyrate after a meal was higher after 2'-FL than after placebo, and plasma acetate rose in lean men only. Whether this leads to any health effect was not tested.

3

Small amounts reach the blood

Some 2'-FL is absorbed: it was found in the blood and urine of infants fed 2'-FL formula and of older adults taking 2'-FL. In the older adult trial, people with a larger rise in bifidobacteria had higher plasma 2'-FL. What the absorbed amount does in the body is not known.

Clinical trials

1
2'-FL, LNnT or a Blend at 5 to 20 g a Day in Healthy Adults
PubMed

Randomized, double-blind, placebo-controlled, parallel dose-finding trial over 2 weeks: ten groups of ten took 2'-FL alone, LNnT alone or a 2:1 blend of the two at 5, 10 or 20 g a day, or 2 g glucose placebo (NCT01927900). The 2'-FL was synthetic. Funded by Glycom A/S, which employed three authors and paid three others as consultants (Elison et al. 2016, Br J Nutr)

100 healthy adults aged 18 to 60 in Denmark; all completed.

Bifidobacterium rose more than on placebo with 10 g of 2'-FL alone but not with 5 or 20 g of 2'-FL; it also rose with LNnT and with 10 or 20 g of the blend. All 56 adverse events were mild. At 20 g of 2'-FL alone, nausea, rumbling, bloating, gas, diarrhea, loose stools and urgency scored higher than on placebo.

2
2'-FL 1 or 5 g a Day for 6 Weeks in Older Adults
PubMed

Randomized, placebo-controlled trial, glucose placebo (NCT03690999). Funded by Abbott Nutrition; three authors were Abbott employees, and some authors and Abbott filed a provisional patent on the work (Carter et al. 2025, Cell Rep Med)

89 healthy adults aged 60 to 83.

The primary outcome, change in an immune cytokine response score, did not differ between groups. At week 3, Bifidobacterium was higher on 5 g than on placebo (9.7% vs 3.5%); 1 g did not differ from placebo. HDL cholesterol, fasting insulin and FGF21 rose on 5 g. No gastrointestinal adverse events were reported.

3
2'-FL 3 g a Day for 12 Weeks With Diet and Walking
PubMed

Randomized, double-blind, placebo-controlled trial of Momstamin 2'-F alongside 10,000 steps a day 5 days a week and a 300 kcal a day calorie cut; primary outcomes were body weight, body composition and waist and hip size; registered only after the trial ended (NCT06547801). Funded by Advanced Protein Technologies Corp. through a grant to the university (Ko et al. 2024, Nutrients)

Adults with overweight; 41 of 50 completed follow-up (21 and 20 per group).

Weight loss was similar in both groups, and the primary body composition and size measures did not differ between groups over time (hip size showed only a trend). Fat mass fell from baseline on 2'-FL but not on placebo, a difference the authors say was not significant between groups. Bone mineral content fell slightly on 2'-FL. The supplement was well tolerated.

4
2'-FL 12 g a Day for 8 Weeks After Vancomycin
PubMed

Randomized, double-blind, placebo-controlled trial: 7 days of oral vancomycin, then Biotis 2'-FL (FrieslandCampina) 12 g a day or maltodextrin 6 g a day (NCT04561284). Funded by a Dutch public-private research partnership; one author was a FrieslandCampina employee (Vliex et al. 2025, Gut Microbes)

37 adults with overweight or obesity, without prediabetes.

Recovery of gut bacteria toward baseline was better than on placebo after 2 weeks but no longer differed at 8 weeks. Fasting IL-6 fell more on 2'-FL at 8 weeks. Effects on glucose tolerance and other metabolic measures were small.

5
2'-FL 2 g a Day, Oligofructose or Both for 4 Weeks: Gut Bacteria and Mood
PubMed

Randomized, double-blind, placebo-controlled, four-arm parallel trial against maltodextrin; primary outcomes were gut bacterial load and composition (NCT05212545). Funded by the BENEO-Institute, an oligofructose maker that employed two authors (Jackson et al. 2023, Am J Clin Nutr)

92 healthy working adults with mild to moderate anxiety and low mood scores, 23 per group.

Bifidobacterium and other taxa rose on oligofructose and on the combination; changes on 2'-FL alone varied widely between people. Mood scores improved in the 2'-FL group, but the oligofructose arms improved several mood measures more than 2'-FL alone. No group differed in gas, bloating or abdominal pain.

6
2'-FL and LNnT Blend in Adults With IBS
PubMed

Randomized, double-blind, placebo-controlled parallel trial of a two-HMO blend (4:1 2'-FL and LNnT) at 5 or 10 g a day versus glucose for 4 weeks plus 4 weeks of follow-up; primary outcome fecal bifidobacteria (NCT02875847). Glycom A/S is listed as the grant source and employed four authors (Iribarren et al. 2020, Neurogastroenterol Motil)

60 adults with IBS diagnosed by Rome IV criteria in Sweden; 58 completed.

Bifidobacteria rose at week 4 with 10 g compared with the other groups, but not at week 8. Overall and individual gastrointestinal symptoms did not differ between groups at week 4 or 8, and symptoms did not worsen. 2'-FL was not tested on its own.

7
Infant Formula With 0.2 or 1.0 g/L 2'-FL: Growth and Tolerance
PubMed

Randomized, controlled growth and tolerance trial; all formulas contained galactooligosaccharides, with a nonrandomized breastfed reference group; primary outcome weight gain from day 14 to 119 (NCT01808105). Funded by Abbott Nutrition, which employed all authors (Marriage et al. 2015, J Pediatr Gastroenterol Nutr)

Healthy term infants enrolled by day 5: 189 formula-fed and 65 breastfed, followed to day 119.

Weight, length and head circumference growth did not differ among groups, and the formulas were equally well tolerated. 2'-FL was found in infants' blood and urine. This is a safety and growth result for formula, not a benefit for older children or adults.

8
Infant Formula With a 2'-FL and LNnT Blend: Growth and Parent-Reported Illness
PubMed

Randomized, multicenter trial of formula with 1.0 g/L 2'-FL and 0.5 g/L LNnT, a two-HMO blend, versus the same formula without HMOs to 6 months; primary endpoint weight gain through 4 months (NCT01715246). Sponsored by Nestec Ltd., with several Nestle-employed authors (Puccio et al. 2017, J Pediatr Gastroenterol Nutr)

175 healthy infants aged 0 to 14 days (88 test, 87 control).

Weight gain met noninferiority. In secondary outcomes, parents reported less bronchitis and lower respiratory infection and less antibiotic and antipyretic use in the HMO group, which the authors said needs confirmation. Stools were softer at 2 months.

Side effects and drug interactions

Common Potential side effects

Gas, bloating, rumbling and loose stools are the most reported effects. In healthy adults, 20 g a day of 2'-FL alone raised nausea, bloating, gas, diarrhea and urgency scores above placebo, though scores stayed at mild discomfort or below.
At 1 to 5 g a day for 6 weeks in older adults, no gastrointestinal adverse events were reported, and 2 g a day did not change gas, bloating or abdominal pain compared with placebo in working adults.
In a 12-week trial of 3 g a day during a diet and exercise program, a small decrease in bone mineral content was observed.
In infant formula trials, growth and tolerance were no worse than with standard formula, and EFSA and the FDA have reviewed 2'-FL for use in formula and foods. Adult trials lasted 12 weeks or less.

Important Drug interactions

No drug interaction studies of 2'-FL have been published.
Antibiotics: one trial gave 2'-FL after a course of vancomycin with no safety concerns reported, but the gut bacteria effect did not last to 8 weeks. Take antibiotics as prescribed.
Infants: use 2'-FL only as part of an infant formula or as advised by a pediatrician, and ask a doctor before giving adult supplements to children.

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Frequently asked questions about 2'-Fucosyllactose (2'-FL)

What is 2'-fucosyllactose (2'-FL)?

2'-FL is the most plentiful oligosaccharide in human breast milk. Supplement and formula versions are human-identical copies made by chemical synthesis or by fermentation with genetically modified bacteria, not taken from breast milk. Human enzymes cannot directly break it down, but gut bacteria such as bifidobacteria can use it.

How much 2'-FL has been studied in adults?

Adult trials used 1 to 20 g a day for 2 to 12 weeks. A 5 g dose raised bifidobacteria in older adults while 1 g did not, and 10 g did in younger adults while 5 g did not. At 20 g a day digestive side effects increased. Follow the product label.

Is 2'-FL the same as an HMO blend?

No. Many products and trials combine 2'-FL with LNnT or other milk oligosaccharides. The bowel symptom trials in adults used a 2'-FL and LNnT blend, so their results apply to that blend, not to 2'-FL alone. See the human milk oligosaccharides page for blends.

Is 2'-FL safe?

The FDA has received more than 20 GRAS notices for 2'-FL and responded with no questions to most, and EFSA judged it safe in infant formula and other foods. Adult trials up to 12 weeks found mainly gas and loose stools at high doses. Long-term adult data are lacking.

What is 2'-Fucosyllactose?

2'-Fucosyllactose (2'-FL) is the most plentiful of the oligosaccharides found in human breast milk. The versions sold in infant formula and adult supplements are made either by chemical synthesis or by fermentation with genetically modified bacteria, and the FDA and EFSA have reviewed it for safety.

What is 2'-Fucosyllactose used for?

NutraSmarts does not list 2'-Fucosyllactose under a health category. What the research covers: In two placebo-controlled trials in healthy adults, 2'-FL alone raised gut Bifidobacterium more than placebo at some doses: 10 g a day but not 5 or 20 g over 2 weeks, and 5 g but not 1 g a day at the midpoint of a 6-week trial.

What is the recommended dosage of 2'-Fucosyllactose?

The clinically studied dose is Adult trials of 2'-FL alone used 1 or 5 g a day for 6 weeks, 2 g for 4 weeks, 3 g for 12 weeks, 12 g for 8 weeks and 5, 10 or 20 g for 2 weeks. Infant formulas tested 0.2 to 1.0 g per liter. Always follow the product label and check with a healthcare provider for personal advice.

Does 2'-Fucosyllactose interact with any medications?

Possible interactions include: No drug interaction studies of 2'-FL have been published. Antibiotics: one trial gave 2'-FL after a course of vancomycin with no safety concerns reported, but the gut bacteria effect did not last to 8 weeks. Take antibiotics as prescribed. If you take prescription medication, check with a pharmacist or doctor before using it.

How strong is the scientific evidence for 2'-Fucosyllactose?

NutraSmarts rates the evidence for 2'-Fucosyllactose as Limited (2 out of 5). It is backed by 8 study summaries and 16 cited references summarized on this page. A higher rating reflects more, larger, and better-designed human studies.

References(16 citations)

Evidence ratings on NutraSmarts are based on the totality of human clinical research, with emphasis on randomized controlled trials, meta-analyses, and systematic reviews. The references below directly support claims made throughout this page.

  1. Elison E, Vigsnaes LK, Rindom Krogsgaard L, Rasmussen J, Sørensen N, McConnell B, Hennet T, Sommer MO, Bytzer P. Oral supplementation of healthy adults with 2'-O-fucosyllactose and lacto-N-neotetraose is well tolerated and shifts the intestinal microbiota. Br J Nutr. 2016;116(8):1356-1368. doi: 10.1017/S0007114516003354.PubMedUsed to support: Funded by Glycom A/S, which supplied synthetic 2'-FL (99.9% pure) and LNnT; three authors were Glycom employees and three were paid Glycom consultants (NCT01927900). Double-blind, placebo-controlled, dose-finding trial in 100 healthy adults, ten groups of ten, taking 2'-FL alone, LNnT alone or a 2:1 2'-FL and LNnT blend at 5, 10 or 20 g a day, or 2 g glucose placebo, for 2 weeks. Bifidobacterium rose more than on placebo with 10 g of 2'-FL alone (not with 5 or 20 g of 2'-FL), with all three LNnT doses and with 10 or 20 g of the blend. Fifty-six adverse events in 44 people were all mild; at 20 g of 2'-FL alone, nausea, rumbling, bloating, gas, diarrhea, loose stools and urgency scored higher than on placebo, though mean scores stayed at mild discomfort or below.
  2. Carter MM, Demis D, Perelman D, St Onge M, Petlura C, Cunanan K, Mathi K, Maecker HT, Chow JM, Robinson JL, Sabag-Daigle A, Sonnenburg ED, Buck RH, Gardner CD, Sonnenburg JL. A human milk oligosaccharide alters the microbiome, circulating hormones, and metabolites in a randomized controlled trial of older adults. Cell Rep Med. 2025;6(8):102256. doi: 10.1016/j.xcrm.2025.102256.PubMedUsed to support: Funded by Abbott Nutrition; three authors were Abbott employees, and some authors and Abbott filed a provisional patent on the work (NCT03690999). Randomized, placebo-controlled trial in 89 healthy adults aged 60 and over taking 1 g or 5 g of 2'-FL a day or a glucose placebo for 6 weeks. The primary outcome, change in an immune cytokine response score, did not differ between groups. At week 3, Bifidobacterium was higher on 5 g than on placebo (9.7% vs 3.5% relative abundance) while 1 g did not differ from placebo; HDL cholesterol, fasting insulin and FGF21 rose on 5 g. 2'-FL was reported as well tolerated with no gastrointestinal adverse events.
  3. Ko J, Yoo C, Xing D, Chun J, Gonzalez DE, Dickerson BL, Leonard M, Jenkins V, van der Merwe M, Slupsky CM, Sowinski R, Rasmussen CJ, Kreider RB. Effects of Human Milk Oligosaccharide 2'-Fucosyllactose Ingestion on Weight Loss and Markers of Health. Nutrients. 2024;16(19):3387. doi: 10.3390/nu16193387.PubMedUsed to support: Funded by Advanced Protein Technologies Corp. (Korea) through a research grant to Texas A&M University; the authors reported no financial conflicts with the sponsor (NCT06547801). Randomized, double-blind, placebo-controlled trial of 3 g a day of Momstamin 2'-F or placebo for 12 weeks alongside a walking program and a 300 kcal a day calorie reduction; 41 of 50 adults with overweight completed follow-up. Body weight, body composition and waist and hip size were the primary outcomes, and none differed between groups over time (multivariate group by time p = 0.760; hip size trend p = 0.060). Fat mass fell from baseline on 2'-FL (1,642 g) but not on placebo, and the authors state the difference between groups was not significant; body fat percentage and fat-free mass showed only within-group trends. Bone mineral content fell below baseline on 2'-FL. The trial was registered after it ended.
  4. Vliex LMM, Barnett D, Monzel E, Nauta A, Oudhuis GJ, Fassarella M, Holst JJ, Zoetendal EG, Penders J, Blaak EE. 2'-Fucosyllactose supplementation results in a transient improvement in gut microbial resilience after vancomycin use in adults with overweight or obesity: a randomized, double-blind, placebo-controlled intervention. Gut Microbes. 2025;17(1):2580693. doi: 10.1080/19490976.2025.2580693.PubMedUsed to support: Funded by the Dutch Research Council and the Carbohydrate Competence Center public-private partnership; one author was a FrieslandCampina employee (NCT04561284). 37 adults with overweight or obesity took oral vancomycin for 7 days, then 12 g a day of Biotis 2'-FL (FrieslandCampina) or 6 g a day of maltodextrin for 8 weeks. Recovery of gut bacteria toward the starting state was better than on placebo after 2 weeks of 2'-FL but no longer differed at 8 weeks; fasting IL-6 fell more on 2'-FL at 8 weeks, and other metabolic effects were small.
  5. Vliex LMM, Godinho Mimoso IF, Le GN, Blaak EE, Penders J. Modulation of the gut microbiome and resistome by antibiotic use, but not by subsequent 2'-fucosyllactose intake, in adults with overweight or obesity. Gut Microbes. 2026;18(1):2746814. doi: 10.1080/19490976.2026.2746814.PubMedUsed to support: Shotgun sequencing substudy of 18 adults from the vancomycin trial. After 8 weeks, 2'-FL did not improve recovery of gut bacteria compared with placebo and did not change the set of antibiotic resistance genes. The authors declared no conflicts.
  6. Canfora EE, Vliex LMM, Wang T, Nauta A, Bouwman FG, Holst JJ, Venema K, Zoetendal EG, Blaak EE. 2'-fucosyllactose alone or combined with resistant starch increases circulating short-chain fatty acids in lean men and men with prediabetes and obesity. Front Nutr. 2023;10:1200645. doi: 10.3389/fnut.2023.1200645.PubMedUsed to support: Crossover study in 10 lean men and 9 men with prediabetes and overweight or obesity (NCT04795804); one author was a FrieslandCampina employee. A single day of 2'-FL, 2'-FL plus resistant starch, or placebo was given before a test day. Plasma butyrate after a meal rose after 2'-FL versus placebo in both groups, and acetate rose only in lean men. This is a one-day metabolic study, not a test of any health outcome.
  7. Jackson PP, Wijeyesekera A, Williams CM, Theis S, van Harsselaar J, Rastall RA. Inulin-type fructans and 2'fucosyllactose alter both microbial composition and appear to alleviate stress-induced mood state in a working population compared to placebo (maltodextrin): the EFFICAD Trial, a randomized, controlled trial. Am J Clin Nutr. 2023;118(5):938-955. doi: 10.1016/j.ajcnut.2023.08.016.PubMedUsed to support: Funded by the BENEO-Institute (an inulin and oligofructose maker); two authors were BENEO employees (NCT05212545). Five-week, four-arm, double-blind trial in 92 adults with mild to moderate anxiety and low mood scores: 8 g oligofructose, 2 g 2'-FL, both, or 10 g maltodextrin a day. Primary outcomes were gut bacterial load and composition. Changes in bacteria on 2'-FL alone varied widely between people. Mood scores improved in the 2'-FL group, but the oligofructose arms improved several mood measures more than 2'-FL alone. No group differed in gas, bloating, abdominal pain or fullness. PubMed lists a 2024 corrigendum.
  8. Iribarren C, Törnblom H, Aziz I, Magnusson MK, Sundin J, Vigsnaes LK, Amundsen ID, McConnell B, Seitzberg D, Öhman L, Simrén M. Human milk oligosaccharide supplementation in irritable bowel syndrome patients: A parallel, randomized, double-blind, placebo-controlled study. Neurogastroenterol Motil. 2020;32(10):e13920. doi: 10.1111/nmo.13920.PubMedUsed to support: Glycom A/S is listed as the grant source and four authors were Glycom employees (NCT02875847). Double-blind trial in 60 adults with IBS (Rome IV) taking 5 g or 10 g a day of a 4:1 blend of 2'-FL and LNnT, a two-HMO blend, or glucose placebo for 4 weeks. Bifidobacteria, the registered primary outcome, rose at week 4 with 10 g compared with the other groups, but not at week 8. Overall and individual gastrointestinal symptoms did not differ between groups at week 4 or 8, and symptoms did not worsen.
  9. Palsson OS, Peery A, Seitzberg D, Amundsen ID, McConnell B, Simrén M. Human Milk Oligosaccharides Support Normal Bowel Function and Improve Symptoms of Irritable Bowel Syndrome: A Multicenter, Open-Label Trial. Clin Transl Gastroenterol. 2020;11(12):e00276. doi: 10.14309/ctg.0000000000000276.PubMedUsed to support: Sponsored by Glycom, Inc., which helped design the trial and write the paper; three authors were Glycom employees (NCT03550742). Open-label, single-arm trial with no placebo in 317 adults with IBS taking 5 g a day of a 4:1 blend of 2'-FL and LNnT for 12 weeks; 245 completed per protocol. Abnormal stool consistency and symptom scores fell from baseline. The authors called for a placebo-controlled trial. Common side effects were mild gas, abdominal pain and distension.
  10. Marriage BJ, Buck RH, Goehring KC, Oliver JS, Williams JA. Infants Fed a Lower Calorie Formula With 2'FL Show Growth and 2'FL Uptake Like Breast-Fed Infants. J Pediatr Gastroenterol Nutr. 2015;61(6):649-58. doi: 10.1097/MPG.0000000000000889.PubMedUsed to support: Funded by Abbott Nutrition; all authors were Abbott employees (NCT01808105). Randomized trial in healthy term infants fed formula with galactooligosaccharides alone or with 0.2 or 1.0 g/L of 2'-FL from enrollment to day 119, with a breastfed reference group (189 formula-fed and 65 breastfed infants). Weight, length and head growth did not differ among groups, the formulas were equally well tolerated, and 2'-FL appeared in infants' blood and urine.
  11. Goehring KC, Marriage BJ, Oliver JS, Wilder JA, Barrett EG, Buck RH. Similar to Those Who Are Breastfed, Infants Fed a Formula Containing 2'-Fucosyllactose Have Lower Inflammatory Cytokines in a Randomized Controlled Trial. J Nutr. 2016;146(12):2559-2566. doi: 10.3945/jn.116.236919.PubMedUsed to support: Substudy of the Abbott infant formula trial above (NCT01808105); authors were from Abbott Nutrition and the Lovelace Respiratory Research Institute. At 6 weeks, infants fed formula with 0.2 or 1.0 g/L of 2'-FL had 29 to 83% lower plasma inflammatory cytokines than infants fed the control formula, similar to breastfed infants. These are immune markers in infants, not infections or illness outcomes.
  12. Puccio G, Alliet P, Cajozzo C, Janssens E, Corsello G, Sprenger N, Wernimont S, Egli D, Gosoniu L, Steenhout P. Effects of Infant Formula With Human Milk Oligosaccharides on Growth and Morbidity: A Randomized Multicenter Trial. J Pediatr Gastroenterol Nutr. 2017;64(4):624-631. doi: 10.1097/MPG.0000000000001520.PubMedUsed to support: Sponsored by Nestec Ltd., which supplied the formula; several authors were from Nestle units (NCT01715246). Healthy infants were randomized to formula with 1.0 g/L 2'-FL plus 0.5 g/L LNnT, a two-HMO blend (n = 88), or the same formula without HMOs (n = 87) to 6 months. Weight gain through 4 months, the primary endpoint, met noninferiority. Parent-reported bronchitis, lower respiratory infections and antibiotic and antipyretic use were lower in secondary analyses, which the authors said need confirmation.
  13. Shivakoti R, Laughton B, Mandell J, Barrios-Tascon A, Rajendran R, Glashoff R, Bode L, Aldrovandi G, Kuhn L. Limited Evidence of Benefits from Clinical Trials of Human-Identical Milk Oligosaccharides for Infants. Adv Nutr. 2026;17(3):100593. doi: 10.1016/j.advnut.2026.100593.PubMedUsed to support: Independent review of 12 randomized trials of human-identical milk oligosaccharides in infants and young children, most often 2'-FL alone or with other HMOs. All trials in healthy infants showed growth and tolerance no worse than control formula; results on illness were inconsistent and the trials were underpowered for serious illness. The authors reported no conflicts of interest.
  14. EFSA Panel on Dietetic Products, Nutrition and Allergies (NDA). Safety of 2'-O-fucosyllactose as a novel food ingredient pursuant to Regulation (EC) No 258/97. EFSA J. 2015;13(7):4184. doi: 10.2903/j.efsa.2015.4184.PubMedUsed to support: EFSA safety opinion on synthetic 2'-FL. It found no genotoxicity concern, set a no observed adverse effect level of 2,000 mg/kg body weight a day in a 90-day rat study, and concluded 2'-FL is safe in infant and follow-on formula with LNnT at up to 1.2 g/L 2'-FL and in other foods at the uses proposed, which included foods and food supplements for adults. It is a safety opinion, not an efficacy assessment.
  15. EFSA Panel on Nutrition, Novel Foods and Food Allergens (NDA), Turck D, Bohn T, Castenmiller J, De Henauw S, Hirsch-Ernst KI, Maciuk A, Mangelsdorf I, McArdle HJ, Naska A, Pentieva K, Siani A, Thies F, Tsabouri S, Vinceti M, Aguilera-Gómez M, Cubadda F, Frenzel T, Heinonen M, Prieto Maradona M, Marchelli R, Neuhäuser-Berthold M, Peláez C, Poulsen M, Schlatter JR, Siskos A, van Loveren H, Colombo P, Noriega Fernández E, Knutsen HK. Safety of the extension of use of 2'-fucosyllactose (2'-FL) as a novel food pursuant to Regulation (EU) 2015/2283. EFSA J. 2023;21(11):e08334. doi: 10.2903/j.efsa.2023.8334.PubMedUsed to support: EFSA opinion on raising the 2'-FL limits in infant and follow-on formula. It records that 2'-FL is on the EU Union list of novel foods, made by chemical synthesis or by fermentation with genetically modified strains of E. coli K-12 DH1, E. coli BL21(DE3) or Corynebacterium glutamicum, and concludes the extension of use is safe. EFSA notes it does not assess claimed benefits.
  16. U.S. Food and Drug Administration. GRAS Notices inventory: search results for fucosyllactose FDA Human Foods Program (GRAS Notice Inventory). 2026;Online database, accessed November 2026..SourceUsed to support: Not PubMed-indexed; FDA database read in November 2026. Lists more than 20 GRAS notices for 2'-FL closed with 'FDA has no questions', from GRN 546 (Glycom A/S, September 2015; infant formula up to 2,400 mg/L and 12 other food categories) and GRN 571 (Jennewein Biotechnologie, November 2015; infant and toddler formula up to 2 g/L) and GRN 650 (November 2016) through GRN 1298 (June 2026). A few notices were withdrawn at the notifier's request, and GRN 1281 (May 2026) received a response that it did not provide a basis for a GRAS determination.