Benefits
Supports fat digestion when bile acids run short
Bile acids pack the products of fat digestion into tiny micelles that the gut lining can absorb. In published case reports of people who had lost part or all of the ileum, where bile acids are normally recycled, ox bile sharply cut the fat lost in stool, in one patient from 134 to 9 grams a day. These were single patients under medical care, not controlled trials.
Studied for nutrient absorption in short bowel syndrome
In one emaciated patient with short bowel syndrome and an ileostomy, a bile acid mixture from ox bile raised fat absorption by roughly 40 grams a day and improved calcium absorption, and over four months at 2 g per meal her weight climbed from 80 to 98 pounds. This is specialist, supervised use in a rare condition and says little about ordinary digestion.
After gallbladder removal: popular, but untested
Ox bile is marketed widely to people without a gallbladder, yet no trial has tested it in that group. The liver keeps making bile after the operation. One comparison found stool fat ran higher in men after cholecystectomy than in matched controls, but it tested no supplement. In one series, 25 of 26 people with chronic diarrhea after the surgery had bile acid malabsorption, which extra bile acids could worsen.
Bowel tolerance depends on how much bile reaches the colon
Unabsorbed bile acids that reach the colon draw in water and can cause diarrhea. In one patient with a remaining colon, stool weight did not rise on ox bile extract even as fat loss fell, but in a small Austrian series two patients with a colon had greatly worsened diarrhea on ox bile extracts. Anyone prone to loose stools should start low or skip it.
Bacterial overgrowth claims rest on rat data
Some brands suggest a bedtime capsule to keep small intestinal bacteria in check. Bile acids do have antimicrobial effects, and in rats with cirrhosis two weeks of oral conjugated bile acids returned ileal bacterial counts to normal and reduced bacterial translocation. Those rats received purified bile acids, not ox bile, and no human trial has tested ox bile for bacterial overgrowth.
Mechanism of action
Mixed micelles carry dietary fat
Conjugated bile acids are detergents. After lipase splits dietary fat, bile acids gather the resulting fatty acids and monoglycerides into mixed micelles that ferry them to the intestinal lining, and fat-soluble vitamins travel the same route. Too little bile acid in the upper gut lets fat, and the calories it carries, pass through unabsorbed.
Ileal recycling sets the size of the bile acid pool
The body reabsorbs bile acids in the terminal ileum and returns them to the liver, so each molecule is reused through several cycles before it is lost. Removing or damaging the ileum breaks that loop, the pool runs down and fat absorption fails. That is the setting of the ox bile case reports; gallbladder removal leaves the loop intact.
Colonic secretion when bile acids overflow
Bile acids that escape absorption and reach the colon in high concentration impair the lining and drive water secretion, producing diarrhea. This is why bile acid binders such as cholestyramine are the standard fix for bile acid diarrhea, and why supplemental bile acids can backfire in people whose colon already receives too many.
Natural bile acids versus a synthetic replacement
Natural conjugated bile acids, the kind in ox bile, are open to bacterial metabolism and can act as a laxative in the colon. Researchers developed cholylsarcosine, a synthetic conjugated bile acid that resists bacterial metabolism and has no cathartic activity, as a gentler replacement for people with bile acid loss.
Clinical trials
Single-patient case report of oral ox bile for severe steatorrhea (Fordtran JS, Bunch F, Davis GR 1982, Gastroenterology 82(3):564-8, PMID 7054048).
One woman with prior colectomy, partial ileectomy and ileostomy for Crohn's disease, with severe fat malabsorption from bile salt deficiency.
Her severe diarrhea improved on loperamide, but steatorrhea and malnutrition persisted until ox bile was added, which corrected both without increasing the diarrhea. The authors noted that bile salt therapy was generally avoided in such patients for fear of causing or worsening diarrhea. One patient, no control group.
Single-patient case report of chronic ox bile extract ingestion (Little KH, Schiller LR, Bilhartz LE, Fordtran JS 1992, Dig Dis Sci 37(6):929-33, PMID 1587199).
One patient with ileectomy and partial right colon resection for Crohn's disease and severe steatorrhea from bile acid malabsorption.
Fecal fat fell from 134 to 9 g per 24 hours, and stool weight did not increase (669 g before therapy, 507 g after). The authors concluded ox bile extract does not necessarily raise stool weight and can be tried with caution. It is a single case, so it cannot predict who will tolerate it.
Metabolic balance studies and a 4-month outpatient trial in one patient (Gruy-Kapral C, Little KH, Fordtran JS, Meziere TL, Hagey LR, Hofmann AF 1999, Gastroenterology 116(1):15-21, PMID 9869597).
One emaciated patient with short bowel syndrome and an ileostomy in whom parenteral nutrition could not be used.
Both a natural conjugated bile acid mixture from ox bile and synthetic cholylsarcosine increased fat absorption by about 40 g a day, calcium absorption rose, and neither caused a clinically significant rise in ileostomy output. On 2 g per meal of the natural bile acids for four months, her weight rose from 80 to 98 lb without side effects.
Uncontrolled balance studies of cholylsarcosine, with ox bile extracts compared in two patients (Kapral C, Wewalka F, Praxmarer V, Lenz K, Hofmann AF 2004, Z Gastroenterol 42(7):583-9, PMID 15248106).
Four short bowel syndrome patients with a residual colon who did not need intravenous feeding; two were also given ox bile extracts.
Cholylsarcosine raised fat absorption from 65.5 to 94.5 g a day with a 26% rise in fecal weight. In the two patients given ox bile extracts, the natural bile acids reduced steatorrhea to a smaller extent and greatly worsened diarrhea. The authors concluded the synthetic bile acid was the efficacious and safe option for patients with a colon.
Clinical series using the SeHCAT bile acid retention test; not a study of ox bile (Sciarretta G, Furno A, Mazzoni M, Malaguti P 1992, Am J Gastroenterol 87(12):1852-4, PMID 1449156).
33 patients after cholecystectomy, 26 of them with chronic diarrhea.
Marked bile acid malabsorption was found in 25 of the 26 patients with diarrhea, and the bile acid binder cholestyramine at 2 to 12 g a day was effective in 23 of 25. Adding bile acids runs opposite to the treatment that worked here, and ox bile has never been tested in this group.