Examining the Effects of Diet Composition, Soluble Fiber, and Species on Total Fecal Excretion of Bile Acids: A Meta-Analysis.

Bile acids (BA) are produced in the liver and conjugated with glycine or taurine before being released into the small intestine to aid with lipid digestion. However, excessive BA losses through feces can occur due to several dietary factors that in turn require greater production of BA by the liver due to a reduction in BA recycling. Consequently, net utilization of taurine and/or glycine is increased. To quantify this impact, we conducted a meta-analysis to investigate the effect of soluble fiber, diet composition, and species on fecal excretion of BA. After a systematic review of the literature, twelve studies met all inclusion criteria. Dietary carbohydrate, protein, fat, cellulose, cholesterol, soluble fiber and animal species were tested as independent variables. Mixed models were developed treating study as a random effect, and fixed effect variables were retained at P < 0.05 significance and where collinearity was absent between multiple X variables. A total of ten studies comprised of four species [(rat = 5), hamster (n = 1), guinea pig (n = 3) and dog (n = 1)], and 30 observations were evaluated in the final models after outlier removal. Model evaluation was based on the corrected Akaike Information Criteria, the concordance correlation coefficient and the root mean square prediction error. Three base models were developed, examining carbohydrate, protein and fat impacts separately. The best fitting models included the fixed effect of species and the interaction between soluble fiber (yes/no) and dietary carbohydrate, protein or fat (%, as-fed). Increased concentrations of dietary protein and fat resulted in greater fecal excretion of BA (P < 0.05). Conversely, increasing levels of dietary carbohydrate led to lower excretions of BA (P < 0.05). Increased dietary soluble fiber containing ingredients resulted in greater excretion of BA in all models (P < 0.05). Rats had greater excretion of BA compared to hamsters and guinea pigs (P < 0.05) in all models, and also compared to dogs (P < 0.05) in the carbohydrate model. The findings from this meta-analysis indicate that not only soluble fiber, but also increasing levels of dietary fat and protein may result in greater fecal excretion of BA, potentially altering taurine and/or glycine metabolism and affecting the need for diet delivery of these AA.

La diarrea inducida con lactosa es mas severa, prolongada y produce mayores pérdidas fecales de macronutrientes en ratas cecotomizadas que en ratas intactas / Lactose-induced diarrhea is more severe, last longer and produces more fecal macronutrient losses in cecectomized than in intact rats

La diarrea inducida con lactosa en ratas ha servido para estudiar la alimentación durante la diarrea. Sin embargo, las ratas se adaptan al consumo de lactosa por lo que la diarrea dura aproximadamente una semana. Para establecer si la remoción del ciego podría prolongarla, aquí se comparó esta diarrea en ratas intactas y cecotomizadas. El experimento incluyó 16 ratas intactas y 16 cecotomizadas. A la mitad de las ratas en cada grupo se les ofreció una dieta con 45% de lactosa (grupo diarrea) y a la otra mitad una dieta sin lactosa (grupo control). El experimento duró 21 días con 3 recolecciones de heces de 48 h (días 2-4, 9-11 y 17-19). Los resultados mostraron que durante la primera recolección hubo diarreas similares tanto en los grupos de ratas intactas como cecotomizadas, pero en las próximas, sólo las cecotomizadas tenían una diarrea cuya severidad aumentó (3,5 veces) con el tiempo. Adicionalmente, en los dos tipos de ratas, las pérdidas fecales de proteína y grasa fueron proporcionales a la masa fecal húmeda excretada, pero fueron 2 veces más altas en las cecotomizadas. Se concluye que la cecotomía previene la adaptación, aumenta la severidad y prolonga la diarrea inducida con lactosa e incrementa notablemente las pérdidas fecales de los macronutrientes y reduce la eficiencia del alimento(AU)

Lactose induced diarrhea in rats has been used for studying the appropriated feeding during diarrhea. However, rats adapt to lactose and this diarrhea last approximately one week. In order to establish if cecum removal could prolong it, here lactose induced diarrhea was produced in intact and cecectomized rats. In the experiment there were 16 intact and 16 cecectomized rats. Halve of the rats in each group were fed a diet with 45% lactose (Diarrhea group) and the other halve a lactose free diet (Control group). The experiment lasted 21 days and included three 48h fecal collections (days 2-4, 9-11 and 17-19). The results showed that during the first collection both groups had diarrheas of similar severity but thereafter, only the cecectomized had a diarrhea whose severity increased (3.5 times) with time. Additionally, in both groups of rats, protein and fat fecal losses were proportional to fecal output but they were higher (2 times) in the cecectomized group. In conclusion, cecectomy prevents lactose adaptation and results in a diarrhea that last longer and it is more severe (3.5 times). Also in these rats fecal losses of macronutrients are higher whereas feed efficiency is lower(AU)

Refractory celiac disease and EATL patients show severe malnutrition and malabsorption at diagnosis.

BACKGROUND & AIMS: Refractory celiac disease type II (RCDII) and EATL (Enteropathy Associated T-cell Lymphoma) are (pre)malignant complications of celiac disease (CD). Data on malnutrition and intestinal absorption is lacking in these patients. Therefore, the aim of the study is to comprehensively assess nutritional status and intestinal absorption capacity of patients with RCDII and EATL, compared with data of newly diagnosed CD patients. METHODS: Observational study in tertiary care setting in RCDII (n = 24, 63.8 ± 8.2 y), EATL (n = 25, 62.3 ± 5.7 y) and CD patients (n = 43, 45.6 ± 14.8 y). At diagnosis, anthropometry (BMI, unintentional weight loss, fat-free mass index (FFMI), handgrip strength (HGS), nutritional intake, fecal losses and Resting Energy Expenditure (REE)) were assessed. RESULTS: Low BMI (<18.5) was more often observed in RCDII patients than in CD or EATL patients (in 33%, 12% and 12%, respectively, p = 0.029). EATL patients more frequently had unintentional weight loss (>10%) than CD or RCDII patients (in 58%, 19% and 39% of patients, respectively; p = 0.005/0.082). Energy malabsorption (<85%) was detected in 44% and 33% of RCDII and EATL patients, vs 21.6% in CD (NS). Fecal energy losses were higher in RCDII than in CD patients (589 ± 451 vs 277 ± 137 kcal/d, p = 0.017). REE was underestimated by predicted-REE with>10% in 60% of RCDII, 89% of EATL, and 38% of CD patients (p = 0.006). Low FFMI and HGS were detected in one third and two thirds of all patients, respectively. CONCLUSIONS: The nutritional status of patients with RCDII and EATL is inferior compared with untreated naïve CD patients at presentation. Both malabsorption as well as hypermetabolism contribute to malnutrition.