Effect of lactulose and fiber-rich diets on bile in relation to gallstone disease: an update

The potential role of lactulose pharmacotherapy in the treatment and prevention of diabetes

The non-absorbable disaccharide lactulose is mostly used in the treatment of various gastrointestinal disorders such as chronic constipation and hepatic encephalopathy. The mechanism of action of lactulose remains unclear, but it elicits more than osmotic laxative effects. As a prebiotic, lactulose may act as a bifidogenic factor with positive effects in preventing and controlling diabetes. In this review, we summarized the current evidence for the effect of lactulose on gut metabolism and type 2 diabetes (T2D) prevention. Similar to acarbose, lactulose can also increase the abundance of the short-chain fatty acid (SCFA)-producing bacteria Lactobacillus and Bifidobacterium as well as suppress the potentially pathogenic bacteria Escherichia coli. These bacterial activities have anti-inflammatory effects, nourishing the gut epithelial cells and providing a protective barrier from microorganism infection. Activation of peptide tyrosine tyrosine (PYY) and glucagon-like peptide 1 (GLP1) can influence secondary bile acids and reduce lipopolysaccharide (LPS) endotoxins. A low dose of lactulose with food delayed gastric emptying and increased the whole gut transit times, attenuating the hyperglycemic response without adverse gastrointestinal events. These findings suggest that lactulose may have a role as a pharmacotherapeutic agent in the management and prevention of type 2 diabetes via actions on the gut microbiota.

Gastrointestinal defects in gallstone and cholecystectomized patients

BACKGROUND AND AIM

Several gallstone patients complain of dyspeptic symptoms, irrespective of the presence of typical colicky pain. Symptoms often persist after a cholecystectomy. Systematic studies on dyspepsia and dynamic gastrointestinal motor function are missing in gallstone patients with preserved gallbladder or after a cholecystectomy.

MATERIALS AND METHODS

Forty-six gallstone patients (age 55 ± 2 years; 15M, 31F) and 24 cholecystectomized patients (age 57 ± 2 years; 6M, 18F) (no difference in type and volume of gallstones between the two groups) were compared against a group of 65 healthy controls (age 51 ± 2 years; 30M, 35F). Dyspepsia occurring in the prior months was assessed by a questionnaire, gastric and gallbladder emptying by functional ultrasonography and orocecal transit time by a hydrogen breath test using a lactulose-enriched standard liquid meal.

RESULTS

Gallstone patients had significantly greater dyspepsia, fasting and residual gallbladder volumes, and slower gallbladder emptying, gastric emptying and small intestinal transit time than controls. In cholecystectomized patients, gastric emptying further delayed, compared to gallstone patients and controls.

CONCLUSION

Gallstone patients with the gallbladder "in situ" or after a cholecystectomy display dyspeptic symptoms. Symptoms are associated with multiple gastrointestinal motility defects involving the gallbladder, stomach and small intestine. After cholecystectomy, gastric emptying worsens.

Long-term intake of dietary fiber and decreased risk of cholecystectomy in women

BACKGROUND

Epidemiologic studies on the relationship between dietary fiber and gallstone disease are inconclusive, and the effects of different types of dietary fiber are not clear.

METHODS

We examined the association between long-term intake of dietary fiber as well as fiber from different sources and risk of cholecystectomy in a cohort of 69,778 women who were aged from 35 to 61 years in 1984 and had no history of gallstone disease. As part of the Nurses' Health Study, the women reported on questionnaires mailed to them every two years both their fiber intake and whether they had undergone cholecystectomy.

RESULTS

During 16 yr of follow-up, we documented 5,771 cases of cholecystectomy. After adjusting for age and other known or suspected risk factors in a multivariate model, compared with women in the lowest quintile of total dietary fiber intake, the relative risk of choleystectomy for those in the highest quintile was 0.87 (95% CI, 0.78-0.96, p for trend = 0.005). For a 5-g increase in total fiber intake, the multivariate relative risk was 0.94 (95% CI, 0.90-0.98). Insoluble fiber, taking soluble fiber into account in the multivariate model, was significantly associated with a reduced risk. The multivariate relative risk was 0.83 (95% CI, 0.73-0.94, p for trend = 0.009) for insoluble fiber, and was 1.01 (95% CI, 0.89-1.15, p for trend = 0.9) for soluble fiber, when extreme quintiles were compared. For a 5-g increase in intake, the relative risk was 0.90 (95% CI, 0.84-0.97) for insoluble fiber, and was 1.01 (95% CI, 0.83-1.23) for soluble fiber.

CONCLUSIONS

Our results suggest that increased long-term consumption of dietary fiber, particularly insoluble fiber, can reduce risk of cholecystectomy in women.

Glucomannan minimizes the postprandial insulin surge: a potential adjuvant for hepatothermic therapy

Glucomannan (GM) is differentiated from other soluble fibers by the extraordinarily high viscosity of GM solutions. Administration of 4-5g of GM with meals, blended into fluid or mixed with food, can slow carbohydrate absorption and dampen the postprandial insulin response by up to 50%. Controlled clinical studies document that GM can promote satiety and weight loss, lower LDL cholesterol, improve diabetic control, and correct constipation, with minimal if any side-effects. Rodent studies suggest that GM may have potential for decreasing cancer risk and possibly even slowing the ageing process. Hepatothermic therapy, a technique for achieving rapid loss of body fat by optimizing the liver's capacity for fat oxidation, can only achieve its optimal efficacy if diurnal insulin levels are kept low; ingestion of GM with meals will evidently be of benefit in this regard by moderating postprandial insulin surges.

Gallstones and cholecystectomy in modern Britain

BACKGROUND

It has been suggested that gallstone disease is now commoner, and that this might explain an increase in cholecystectomy rates, though conclusive evidence has been lacking.

METHODS

All the non-forensic necropsy results for Dundee 1953-98 were examined to assess the prevalence of gallstone disease. The NHS Scotland annual cholecystectomy figures were extracted from their earliest availability in 1961 up to the present. The subgroup of patients from Dundee was analysed separately, as were laparoscopic procedures, which were recorded from 1991.

RESULTS

Gallstone disease was much commoner in 1974-98 than in 1953-73. Increasing age was the main determinant of gallstone disease. Though gallstone disease was commoner in women than men aged 40-89, there was no sex difference under 40 or over 90 years. Cholecystectomy became much commoner in the 1960s when frequency of gallstone disease did not change. It increased further in the 1970s, peaking in 1977-8. There was a gradual fall in rates in the 1980s when gallstone prevalence remained high. There was a further moderate rise in the 1990s after the wide introduction of laparoscopic cholecystectomy. Cholecystectomy is now much commoner in young women and this change started in the 1960s. By contrast, cholecystectomy in men has become more prevalent in the older age group.

CONCLUSIONS

Gallstones were definitely more common in both sexes at all ages over 40 in the last 25 years. Changes in the cholecystectomy rates are only partly explained by changes in gallstone prevalence, and are more determined by surgical practice.