Soluble dietary fiber protects against cholesterol gallstone formation

Beyond the Bowl: Understanding Amino Acid Requirements and Digestibility to Improve Protein Quality Metrics for Dog and Cat Foods

The determination of amino acid (AA) requirements for mammals has traditionally been done through nitrogen (N) balance studies, but this technique underestimates AA requirements in adult animals. There has been a shift toward researchers using the indicator amino acid oxidation (IAAO) technique for the determination of AA requirements in humans, and recently in dogs. However, the determination of AA requirements specific to adult dogs and cats at maintenance is lacking and the current requirements outlined by the National Research Council are based on a dearth of data and are likely underreporting the requirements of indispensable AA (IAA) for the population. To ensure the physiological requirements of our cats and dogs are met, we need methods to accurately and precisely measure digestibility. In vivo methods, such as ileal cannulation, are most commonly used, however, due to ethical considerations, we are moving away from animal models and toward in vitro methods. Harmonized static digestion models have the potential to replace in vivo methods but work needs to be done to have these methods more accurately represent the gastrointestinal tract (GIT) of cats and dogs. The Digestible IAA Score (DIAAS) is one metric that can help define protein quality for individual ingredients or mixed diets that uses AA SID estimates and ideally those can be replaced with in vitro AA digestibility estimates. Finally, we need accurate and reliable laboratory AA analyses to measure the AA present in complete diets, especially those used to quantify methionine (Met) and cysteine (Cys), both often limiting AAs in cat and dog diets. Together, this will guide accurate feed formulation for our companion animals to satisfy requirements while avoiding over-supplying protein, which inevitably contributes to excess N excretion, affecting both the environment and feed sustainability.

Dietary fiber intake and risk of gallstone: a case-control study

BACKGROUND

Gallstone disease (GSD) and its complications are major public health issues globally. Although many community-based studies had addressed the risk factors for GSD, little is known about the associations between dietary factors and risk of disease. The present study aimed to investigate the potential associations between dietary fibers with the risk of gallstone disease.

METHODS

In this case-control study, 189 GSD patients with less than one month of diagnosis and 342 age‑matched controls were enrolled. Dietary intakes were assessed using a 168-item semi-quantitative validated food frequency questionnaire. Crude and multivariable-adjusted hazard ratios (HRs) and 95% confidence intervals (CIs) were estimated through cox proportional hazards regression models.

RESULTS

Comparing the highest versus the lowest tertile, significant reverse associations were observed between odds of GSD and each category of dietary fiber intake including total (OR _{T3 vs. T1} = 0.44, 95% CI: 0.37-0.7, P for trend = 0.015), soluble (OR _{T3 vs. T1} = 0.51, 95% CI: 0.3-0.8, P for trend = 0.048) and insoluble (OR _{T3 vs. T1} = 0.56, 95% CI: 0.3-0.9, P for trend < 0.001). The relationship between dietary fiber intake and the risk of gallstones was more prominent in overweight and obese subjects than in subjects with a normal body mass index.

CONCLUSION

Comprehensive assessment of the associations of dietary fiber intake with GSD showed that higher intakes of dietary fiber were significantly associated with reduced GSD risk.

Novel insights into the pathogenic impact of diabetes on the gastrointestinal tract

Type 2 and type 1 diabetes are common endocrine disorders with a progressively increasing incidence worldwide. These chronic, systemic diseases have multiorgan implications, and the whole gastrointestinal (GI) tract represents a frequent target in terms of symptom appearance and interdependent pathophysiological mechanisms. Metabolic alterations linked with diabetic complications, neuropathy and disrupted hormone homeostasis can lead to upper and/or lower GI symptoms in up to 75% of diabetic patients, with multifactorial involvement of the oesophagus, stomach, upper and lower intestine, and of the gallbladder. On the other hand, altered gastrointestinal motility and/or secretions are able to affect glucose and lipid homeostasis in the short and long term. Finally, diabetes has been linked with increased cancer risk at different levels of the GI tract. The presence of GI symptoms and a comprehensive assessment of GI function should be carefully considered in the management of diabetic patients to avoid further complications and to ameliorate the quality of life. Additionally, the presence of gastrointestinal dysfunction should be adequately managed to improve metabolic homeostasis, the efficacy of antidiabetic treatments and secondary prevention strategies.

Obesity and Gallstones

BACKGROUND

The prevalence of obesity has been increasing globally and represents the main risk factor for the development of gallstone disease (GD).

SUMMARY

Excess body weight represents the main cause for the development of GD; nevertheless, there have been described multiple risk factors for its development, among them modifiable risk factors as diet, lifestyle, physical inactivity, and non-modifiable risk factors as ethnicity, female sex, advanced age, parity, and genetic mutations. Body mass index, abdominal perimeter, and waist-hip index have been used to determine the degree of adiposity of a person. Hence, central abdominal fat has been mostly associated with insulin resistance with the consequent increase in the hepatic cholesterol secretion; contributing as one of the multiple mechanisms associated with the development of gallstones. This disease has a low mortality; however, it has been associated with multiple diseases such as cardiovascular diseases, carotid atherosclerosis, metabolic associated fatty liver disease, and gallbladder cancer, probably because they share many of the risk factors.

KEY MESSAGES

GD continues to be considered a disease with a high medical burden, in which it is sought to intervene in modifiable risk factors to reduce its development.

Astragalus Polysaccharides Ameliorate Diet-Induced Gallstone Formation by Modulating Synthesis of Bile Acids and the Gut Microbiota

Cholesterol gallstone (CG) disease has relationships with several metabolic abnormalities. Astragalus polysaccharides (APS) have been shown to have multiple benefits against metabolic disorders. We attempted to uncover the effect and mechanism of action of APS on diet-induced CG formation in mice. Animals were fed a chow diet or lithogenic diet (LD) with or without APS supplementation. The effect of APS on CG formation was evaluated. The level of individual bile acids (BAs) in gallbladder bile and ileum were measured by liquid chromatography-tandem mass spectrometry. Real-time reverse transcription-quantitative polymerase chain reaction and western blotting were used to assess expression of the genes involved in BA metabolism and the enterohepatic circulation. Cecal contents were collected to characterize microbiota profiles. APS ameliorated LD-induced CG formation in mice. APS reduced the level of total cholesterol, bile acid hydrophobicity index and cholesterol saturation index in gallbladder bile. The protective effect of APS might result from reduced absorption of cholic acid in the intestine and increased hepatic BA synthesis. APS relieved the LD-induced activation of the intestinal farnesoid X receptor and decreased ileal expression of fibroblast growth factor 15. In the liver, expression of cytochrome P450 (Cyp) enzyme Cyp7a1 and Cyp7b1 was increased, whereas expression of adenosine triphosphate-binding cassette (Abc) transporters Abcg5 and Abcg8 was decreased by APS. APS improved the diversity of the gut microbiota and increased the relative abundance of the Bacteroidetes phylum. APS had demonstratable benefits against CG disease, which might be associated with enhanced BA synthesis and improved gut microbiota. Our results suggest that APS may be a potential strategy for the prevention of CG disease.

Gallstones

Gallstone disease is a worldwide medical problem, but the incidence rates show substantial geographical variation, with the lowest rates reported in African populations. Publications in English language on gallstones which were obtained from reprint requests and PubMed database formed the basis for this paper. Data extracted from these sources included authors, country, year of publication, age and sex of patients, pathogenesis, risk factors for development of gallstones, racial distribution, presenting symptoms, complications and treatment. Gallstones occur worldwide, however it is commonest among North American Indians and Hispanics but low in Asian and African populations. High biliary protein and lipid concentrations are risk factors for the formation of gallstones, while gallbladder sludge is thought to be the usual precursor of gallstones. Biliary calcium concentration plays a part in bilirubin precipitation and gallstone calcification. Treatment of gallstones should be reserved for those with symptomatic disease, while prophylactic cholecystectomy is recommended for specific groups like children, those with sickle cell disease and those undergoing weight-loss surgical treatments. Treatment should be undertaken for a little percentage of patients with gallstones, as majority of those who harbor them never develop symptoms. The group that should undergo cholecystectomy include those with symptomatic gallstones, sickle cell disease patients with gall stones, and patients with morbid obesity who are undergoing laparotomy for other reasons.

Anti-cholelithogenic effect of dietary tender cluster beans (Cyamopsis tetragonoloba) on the formation of cholesterol gallstones in mice

Providing a lithogenic diet that contains 0.5% cholesterol to experimental mice for 10 weeks resulted in cholesterol supersaturation in gallbladder bile, which induced the formation of cholesterol gallstones. In this study, to evaluate the anti-cholelithogenic potential of dietary tender cluster bean, a freeze-dried powder of the test legume was included in the lithogenic diet at 5%, 10%, and 15%. Dietary cluster beans reduced the cholesterol gallstone incidence by 43%, 46%, and 58% at the respective doses. Dietary cluster beans markedly reduced biliary cholesterol and, hence, the cholesterol saturation index. This was corroborated by the beneficial modification of the cholesterol/phospholipid ratio and the cholesterol/bile acid ratio in the bile. Dietary cluster beans countered the alterations in serum and liver cholesterol and lipid profiles caused by the lithogenic diet. Thus, dietary tender cluster beans exerted an anti-cholelithogenic influence by decreasing cholesterol hypersecretion into bile and, hence, the cholesterol saturation index, decreasing the formation of lithogenic bile in experimental mice.

Assessment of characteristics of patients with cholelithiasis from economically deprived rural Karachi, Pakistan

Background

Gallstones have been regarded as one of the most expensive diseases in Gastroenterology, posing a great economic burden on developing nations. The majority of Pakistani people live in rural areas where healthcare facilities are not available or are very primitive. We aim to assess the characteristics among cholelithiasis patients from rural Karachi so that a prevention campaign can be launched in rural underprivileged settings to reduce the economic burden of this preventable disease.

Method

A total of 410 patients were included in the study after giving verbal consent as well as written consent. Variables such as age, weight, height, body mass index (BMI), blood pressure, waist circumference, number of children, monthly family income, number of siblings, and number of family members, were considered in this questionnaire. All data was analysed by SPSS ver. 16.0. Mean and standard deviation (SD) were calculated for continuous variables. Frequency and percentages were calculated for categorical variables.

Results

Nearly 85.4% of the participants were female. The mean ± S.D. for age was 43.8 ± 9.59. Nearly 61% of the patients were illiterate. All of our patients were from low socioeconomic status and their mean salary ± S.D. was 6915 ± 1992 PKR (1 US $ = 90.37PKR). 75% of them were smokers with mean consumption ± S.D. of 7.5 ± 10 cigarettes per day. Fibre in diet was not used by 83.65% of patients. 40.2% were living in combined families. 61% were living in purchased homes. A positive history of diabetes mellitus was given by 45.1%, family history of cholelithiasis by 61% and history of hypertension by 31.7% of subjects. Soft drink consumption was given by 45.1% of patients; while only 8.5% used snacked daily. Tea was consumed by 95.1% of the subjects. Daily physical activity for 30 minutes was reported by only 13.4% of participants.

Conclusion

In conclusion, rural dwellers from low socioeconomic strata are neglected patients and illiteracy further adds fuel to the fire by decreasing the contact with the health professionals. Assessment of the characteristics are very important because considering the great socio-economic burden, an intervention strategy in the form of mass media campaign as well as small group discussions in such rural areas can be formulated and applied to high risk populations to reduce the burden and complications of gallstone disease.

Dietary fenugreek and onion attenuate cholesterol gallstone formation in lithogenic diet-fed mice

An animal study was conducted to evaluate the antilithogenic effect of a combination of dietary fenugreek seeds and onion. Lithogenic conditions were induced in mice by feeding them a high (0.5%) cholesterol diet (HCD) for 10 weeks. Fenugreek (12%) and onion (2%) were included individually and in combination in this HCD. Fenugreek, onion and their combination reduced the incidence of cholesterol gallstones by 75%, 27% and 76%, respectively, with attendant reduction in total cholesterol content by 38-42%, 50-72% and 61-80% in serum, liver and bile respectively. Consequently, the cholesterol/phospholipid ratio was reduced significantly in serum, liver and bile. The cholesterol saturation index of bile was reduced from 4.14 to 1.38 by the combination of fenugreek and onion and to 2.33 by onion alone. The phospholipid and bile acid contents of the bile were also increased. Changes in the hepatic enzyme activities (3-hydroxy-3-methylglutaryl Coenzyme A reductase, cholesterol-7α-hydroxylase and cholesterol-27-hydroxylase) induced by HCD were countered by fenugreek, onion and their combination. Hepatic lipid peroxides were reduced by 19-22% and 39-45% with fenugreek, onion and their combination included in the diet along with the HCD. Increased accumulation of fat in the liver and inflammation of the gallbladder membrane produced by HCD were reduced by fenugreek, onion and their combination. The antilithogenic influence was highest with fenugreek alone, and the presence of onion along with it did not further increase this effect. There was also no additive effect of the two spices in the recovery of antioxidant molecules or in the antioxidant enzyme activities.

Fenugreek seeds reduce atherogenic diet-induced cholesterol gallstone formation in experimental mice

Dietary hypocholesterolemic adjuncts may have a beneficial role in the prevention and treatment of cholesterol gallstones (CGS). In this investigation, fenugreek (Trigonella foenum-graecum) seed was evaluated for this potential on the experimental induction of CGS in laboratory mice. CGS was induced by maintaining mice on a lithogenic diet (0.5% cholesterol) for 10 weeks. Fenugreek seed powder was included at 5%, 10%, and 15% of this lithogenic diet. Dietary fenugreek significantly lowered the incidence of CGS in these mice; the incidence was 63%, 40%, and 10% in the 5%, 10%, and 15% fenugreek groups, respectively, compared with 100% in the lithogenic control. The antilithogenic influence of fenugreek is attributable to its hypocholesterolemic effect. Serum cholesterol level was decreased by 26%-31% by dietary fenugreek, while hepatic cholesterol was lowered by 47%-64% in these high cholesterol-fed animals. Biliary cholesterol was 8.73-11.2 mmol/L as a result of dietary fenugreek, compared with 33.6 mmol/L in high-cholesterol feeding without fenugreek. Cholesterol saturation index in bile was reduced to 0.77-0.99 in fenugreek treatments compared with 2.57 in the high-cholesterol group. Thus, fenugreek seed offers health-beneficial antilithogenic potential by virtue of its favourable influence on cholesterol metabolism.

Dietary fenugreek seed regresses preestablished cholesterol gallstones in mice

An animal study was carried out to evaluate the influence of dietary fenugreek seeds on regression of preestablished cholesterol gallstones (CGS). CGS was induced by feeding a high-cholesterol diet for 10 weeks. After CGS induction, the animals were maintained for a further 10 weeks on experimental diets of high cholesterol, 6% fenugreek powder, 12% fenugreek powder, or basal control. Incidence of CGS and its severity were evaluated at the end of this feeding regimen. The incidence of CGS was significantly lowered as a result of dietary fenugreek seeds, the extent of regression being 61% and 64% in the low and high dose groups compared with 10% regression in the basal control group. The antilithogenic influence of dietary fenugreek was accompanied by significant reductions of more than 35% in serum cholesterol concentration. Hepatic cholesterol concentration was also profoundly lowered by dietary fenugreek, being 53%–63% lower than that of the basal control diet. Biliary cholesterol concentration was significantly lower as a result of dietary fenugreek during the post-CGS induction period, resulting in a decreased cholesterol:phospholipid ratio (0.44 and 0.40 compared with 0.79 in the basal control group). Biliary cholesterol : bile acid ratio was lowered by 67% and 73% upon feeding fenugreek, significantly lower than that in the basal control group. The cholesterol saturation index in the bile was also beneficially lowered by fenugreek treatment during the post-CGS induction period (the index was 0.90 and 0.42 compared with 1.86 in the basal control group). The present study provides evidence of the potency of hypolipidemic fenugreek seeds in regressing preestablished CGS, and this beneficial antilithogenic effect is attributable to its primary influence on cholesterol levels. This finding is significant in the context of evolving a dietary strategy to address CGS, which could help in preventing the incidence and regression of existing CGS and controlling possible recurrence.

Role of diet in cholesterol gallstone formation

BACKGROUND

There is a high prevalence of gallstone disease in Western countries as a consequence of genetic, biochemical, and environmental factors. Animal and clinical studies have explored the importance of dietary elements. Overwhelming but conflicting information has been reported about the relationship between specific dietary components and gallstone disease. Although the detailed biochemical pathways have been described in experimental models, human studies are mainly epidemiological.

METHODS

We performed a Medline search with the terms "diet", "gallstones", "cholesterol", "risk factors", including results from 1965 to 2006 and the author's personal library to review the relationship between dietary factors and cholesterol gallstone disease.

RESULTS

We identified over 150 references and present their results with respect to the author's criteria.

CONCLUSIONS

The best delineated relationship between cholesterol gallstones and diet was found in the studies that analyzed total calorie intake, refined sugars and fiber. The possible mechanisms are discussed in base of experimental studies.

Diet as a risk factor for cholesterol gallstone disease

Cholesterol gallstone disease is a common condition in western populations. The etiology is multifactorial with interaction of genetic and environmental factors. Obesity, aging, estrogen treatment, pregnancy and diabetes are consistently associated to a higher risk. A number of dietary factors have been involved in the pathogenesis of cholelithiasis. In this article we summarize several studies that have evaluated the role of diet as a potential risk factor for gallstone formation, including energy intake, cholesterol, fatty acids, fiber, carbohydrates, vitamins and minerals, and alcohol intake. Consumption of simple sugars and saturated fat has been mostly associated to a higher risk, while fiber intake and moderate consumption of alcohol, consistently reduce the risk. The association between cholesterol intake and gallstone disease has been variable in different studies. The effects of other dietary factors are less conclusive; additional studies are therefore necessary to clarify their relevance in the pathogenesis of gallstone disease. Recent discoveries of the role of orphan nuclear receptors in the regulation of fatty acid and hepatic cholesterol metabolism and excretion open new perspectives for a better understanding of the role of dietary constituents on cholesterol gallstone formation. KEY TEACHING POINTS: The etiology of cholesterol gallstone disease is multifactorial with interaction between genome and environment. It has been postulated that dietary constituents are important determinants for the formation of lithogenic bile. Intake of high energy, simple sugar and saturated fat favors gallstone formation. Fiber and moderate consumption of alcohol reduce the risk. The role of orphan nuclear receptors in the regulation of hepatic cholesterol metabolism and excretion open new leads for understanding the role of dietary constituents on cholesterol gallstone formation.

Frequent nut consumption and decreased risk of cholecystectomy in women

BACKGROUND

Gallstone disease is a major source of morbidity in the developed countries. Nuts are rich in several compounds that may protect against gallstone disease.

OBJECTIVE

The association between nut intake and cholecystectomy was examined in a large cohort of women.

DESIGN

We prospectively studied nut (peanuts, other nuts, and peanut butter) consumption in relation to the risk of cholecystectomy in a cohort of 80,718 women from the Nurses' Health Study who were 30-55 y old in 1980 and had no history of gallstone disease. As part of the Nurses' Health Study, the women reported on questionnaires mailed to them every 2 y both their consumption of nuts and whether they had undergone cholecystectomy. The women were followed through 2000.

RESULTS

During 1,393,256 person-years of follow-up from 1980 to 2000, we documented 7831 cholecystectomies. After adjustment for age and other known or suspected risk factors, women who consumed > or =5 units of nuts (1 unit = 1 oz or 28.6 g nuts)/wk (frequent consumption) had a significantly lower risk of cholecystectomy (relative risk: 0.75; 95% CI: 0.66, 0.85; P for trend < 0.0001) than did women who never ate nuts or who ate <1 unit/mo (rare consumption). Further adjustment for fat consumption (saturated fat, trans fat, polyunsaturated fat, and monounsaturated fat) did not materially alter the relation. In analyses examining consumption of peanuts and other nuts separately, both were associated with a lower risk of cholecystectomy.

CONCLUSION

In women, frequent nut consumption is associated with a reduced risk of cholecystectomy.

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.