Evaluation of gastrointestinal transit in rats fed dietary fibres differing in their susceptibility to large intestine fermentation

Diet rich in soluble dietary fibres increases excretion of perfluorooctane sulfonic acid (PFOS) in male Sprague-Dawley rats

Perfluorooctane sulfonic acid (PFOS) belongs to a large group of anthropogenic compounds with high persistency named per- and polyfluorinated substances (PFAS). Widespread use from industry to household appliances and food-contact materials contributes to PFAS exposure with food as the primary source. Association studies suggest that vegetables and fibre rich diet may reduce PFOS levels in humans, but experimental data remain limited. Here, we investigated PFOS uptake and wash-out after seven days of PFOS (3 mg/kg/day) in two groups of rats (N = 12 per group) fed diets either high (HF) or low (LF) in soluble dietary fibres. Two control groups (N = 12/group) were fed the same diets without PFOS. Changes in pH and transit time were monitored alongside intestinal and faecal microbiota composition. We quantified systemic and excreted, linear and branched PFOS. Results revealed significantly lower pH and faster intestinal transit in the HF groups. Importantly, HF rats had lower serum PFOS concentrations and higher PFOS concentrations in caecal content and faeces, indicating a more efficient excretion on the fibre rich diet. In both dietary groups, PFOS affected the gut microbiota composition. Our results suggest that a diet rich in soluble dietary fibres accelerates excretion of PFOS and lowers PFOS concentration in serum.

Refined sorghum flours precooked by extrusion enhance the integrity of the colonic mucosa barrier and promote a hepatic antioxidant environment in growing Wistar rats

The effects of precooked-refined sorghum flour consumption on antioxidant status, lipid profile, and colonic and bone health were evaluated. Twenty-four male Wistar rats were fed with control diet (C), or red or white precooked-refined sorghum based diets (SD) for 60 days. The intake of SD was lower than that of C, but the efficiency of all diets was similar. Rats fed with SD showed lower feces excretion, cecal pH and enzyme activities (β-glucosidase, β-glucuronidase and mucinase) than C. White SD improved intestinal architecture, cell proliferation and apoptosis, upregulated ZO1 and occludin tight junction proteins and stimulated goblet cell differentiation, enhancing the integrity of the mucosa barrier in both proximal and distal colonic mucosa in a better way than red SD. Consumption of SD significantly decreased serum triglyceride levels compared with the C diet. The mineral content of the right femur was not different among diets. The liver enzyme activities (superoxide dismutase, catalase, glutathione reductase, and glutathione peroxidase) did not show differences among diets. Liver reducing power and reduced glutathione/oxidize glutathione ratio were higher for animals consuming SD than C. It can be concluded that the consumption of precooked refined sorghum flours still has beneficial effects for health, mainly at the colonic level, despite the lower phenolics and fibre contents of refined flours with respect to whole grain flours.

Beneficial effects of consumption of acerola, cashew or guava processing by-products on intestinal health and lipid metabolism in dyslipidaemic female Wistar rats

This study assessed the effects of diet supplementation with industrial processing by-products of acerola (Malpighia emarginataD.C.), cashew (Anacardium occidentaleL.) and guava (Psidium guajavaL.) fruit on the intestinal health and lipid metabolism of female Wistar rats with diet-induced dyslipidaemia. Female rats were randomly divided into five groups: healthy control, dyslipidaemic control and dyslipidaemic experimental receiving acerola, cashew or guava processing by-products. Fruit processing by-products were administered (400 mg/kg body weight) via orogastric administration for 28 consecutive days. Acerola, cashew and guava by-products caused body weight reduction (3·42, 3·08 and 5·20 %, respectively) in dyslipidaemic female rats. Dyslipidaemic female rats receiving fruit by-products, especially from acerola, presented decreased faecal pH, visceral fat, liver fat and serum lipid levels, as well as increased faecal moisture, faecal fat excretion, faecalBifidobacteriumspp. andLactobacillusspp. counts and amounts of organic acids in faeces. Administration of the tested fruit processing by-products protected colon and liver from tissue damage (e.g. destruction of liver and colon cells and increased fat deposition in hepatocytes) induced by dyslipidaemic diet. Dietary fibres and phenolic compounds in tested fruit by-products may be associated with these positive effects. The industrial fruit processing by-products studied, mainly from acerola, exert functional properties that could enable their use to protect the harmful effects on intestinal health and lipid metabolism caused by dyslipidaemic diet.

The fate of (13)C-labelled and non-labelled inulin predisposed to large bowel fermentation in rats

The fate of stable-isotope (13)C labelled and non-labelled inulin catabolism by the gut microbiota was assessed in a healthy rat model. Sprague-Dawley male rats were randomly assigned to diets containing either cellulose or inulin, and were fed these diets for 3 days. On day (d) 4, rats allocated to the inulin diet received (13)C-labelled inulin. The rats were then fed the respective non-labelled diets (cellulose or inulin) until sampling (d4, d5, d6, d7, d10 and d11). Post feeding of (13)C-labelled substrate, breath analysis showed that (13)C-inulin cleared from the host within a period of 36 hours. Faecal (13)C demonstrated the clearance of inulin from gut with a (13)C excess reaching maximum at 24 hours (d5) and then declining gradually. There were greater variations in caecal organic acid concentrations from d4 to d6, with higher concentrations of acetic, butyric and propionic acids observed in the rats fed inulin compared to those fed cellulose. Inulin influenced caecal microbial glycosidase activity, increased colon crypt depth, and decreased the faecal output and polysaccharide content compared to the cellulose diet. In summary, the presence of inulin in the diet positively influenced large bowel microbial fermentation.

α-Galactosides present in lupin flour affect several metabolic parameters in Wistar rats

The aim of this study is to evaluate the influence of α-galactosides present in a lupin diet on metabolic parameters in growing Wistar rats.

Extruded whole grain diets based on brown, soaked and germinated rice. Effects on cecum health, calcium absorption and bone parameters of growing Wistar rats. Part I

The influence of diets with whole rice processed ingredients on cecum health, calcium absorption and bone parameters was studied using an animal model.

The effect of Syphacia muris on nutrient digestibility in laboratory rats

This study was carried out to investigate how pinworm infection in rats affects nutrient digestibility in the hosts. Twenty-four male outbred Wistar rats were randomly divided into two groups of 12 rats each. The rats from the first group (GI) were kept in cages with bedding containing pinworm eggs, and the second (control) group (GII) were kept in a separate room in clean, uncontaminated filter-top cages. The animals were put into individual metabolic cages later. Metabolic trials lasted five days and records of animal weight, food ingestion, and faecal weight were taken daily. Based on laboratory analysis of the feed and faecal nutrient content, digestibility values were determined. On day 15 of the experiment, the animals were euthanized. Although Syphacia muris were found in all rats from the GI group, animals exhibited no clinical signs. In our experiment, S. muris infection reduced the overall digestibility of all measured nutrients (P < 0.01). The most significant differences in digestibility were observed in the case of crude fibre and mineral matter (P < 0.01).

Water-insoluble fiber-rich fraction from pineapple peel improves intestinal function in hamsters: evidence from cecal and fecal indicators

Pineapple peel, a byproduct of agricultural processing, contains high levels of water-insoluble fiber-rich fraction (WIFF) (~42%, wt/wt). Our previous work has demonstrated that cellulose, hemicellulose (xylan and xyloglucan), and pectic substances are the major polysaccharides of pineapple-peel WIFF. Based on its chemical composition and unique characteristics, we hypothesized that daily consumption of WIFF would improve intestinal function in hamsters. Male Golden Syrian hamsters were fed a diet supplemented with either 5% cellulose or various amounts of WIFF (2.5%, 5%, or 10%). Activities of fecal bacterial enzymes, short-chain fatty acid concentrations, and microbial number in the cecal content, and also biochemical indicators in the cecal and feces of hamsters, were evaluated in all groups. The supplementation of WIFF in a diet at a level of 2.5% significantly (P < .05) decreased the daily fecal ammonia output; shortened the gastrointestinal transit time; reduced the activities of β-D-glucosidase, β-D-glucuronidase, mucinase, and urease in feces; and also enhanced the total amounts of short-chain fatty acid in the cecal content and the growth of gut microflora such as Lactobacillus spp and Bifidobacterium spp. These results indicate that WIFF could improve cecal ecosystem function of hamsters by reducing the toxic compounds excreted by intestinal microflora. Therefore, pineapple-peel WIFF could be a promising candidate for a functional ingredient beneficial to human intestinal function and health.