There are loads of these articles and it is so difficult to sort out the ones that are significant.

In this article the the supplement was 200 mg/kg per day the omega-3 fatty acids from eicosapentaenoic aka EPA found in fish oil and human milk and docosahexaenoic acid, aka DHA which is also found in fish but can be manufactured. The antilithogenic may be due to an enhancement in the stability of biliary phospholipid-cholesterol vesicles. The conclusion is that fish oil may be of benefit to people with a high risk for gallstone formation or gallstone recurrence. Note that fish oil omega-3 is far more effective that vegetable omega-3 which has high proportion of omega-6 fatty acids. Omega-6 is requires significant resources to absorb and takes priority over omega-3 absorption which results in reduce omega-3 benefits.

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9 people with Gallstones and 9 healthy volunteers given a diet containing 50 g of wheat bran cereal daily in addition to their normal diet, there was an increase from 1 stool daily to 2 or 3 bulky stools per day. Those patients with Gallstones remained on the high bran diet for 6 months or more. The high-bran diet produced a significant reduction in biliary cholesterol values in patients with Gallstones after 4 weeks, and a significant increase in the concentration of high-density lipoprotein-cholesterol in the serum of patients who stayed on the bran for 6 months or longer. In 9 subjects with gallstones who had supersaturation of their bile with cholesterol, biliary cholesterol concentration fell significantly after 4 weeks of increased dietary wheat bran fibre.

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"Differences in Diet and Food Habits Between Patients With Gallstones and Controls," Ortega, Rosa M., Ph.D., et al, The Journal of the American College of Nutrition, 1997;16(1):88-95. In evaluating 54 gallstone patients and 46 controls with two 24-hour dietary recalls and a food frequency questionnaire, the gallstone patients consumed less food per day in grams and less fish and fruits than the control subjects. The gallstone patients had a higher intake of cereals, oils, sugars and meats than did the control subjects and ate fewer meals per day. The gallstone patients tended to omit evening snacks and have larger evening meals. Gallstone patients spent less time walking and more time sleeping than the control subjects. Gallstone patients had greater fluctuations in body weight with greater frequency. The gallstone patients consumed more total calories and fats, especially monounsaturated and saturated fats, and less fiber, folate and magnesium than the control subjects. Women with gallstones had significantly higher levels of total fats, monounsaturated fats, saturated fatty acids, and cholesterol and significantly lower intakes of fiber, folate, magnesium, calcium and vitamin C than control women. Gallstone patients showed a greater percentage of intake of vitamins and minerals below the recommended daily amounts.