Prebiotic and synbiotic effects on rats fed malted barley with selected bacteria strains.

Butyric acid, one of the key products formed when β-glucans are degraded by the microbiota in the colon, has been proposed to be important for colonic health. Glutamine bound to the fibre may have similar effects once it has been liberated from the fibre in the colon. Both β-glucans and glutamine are found in high amounts in malted barley. Lactobacillus rhamnosus together with malt has been shown to increase the formation of butyric acid further in rats

Carboxylic acids in the hindgut of rats fed highly soluble inulin and Bifidobacterium lactis (Bb-12), Lactobacillus salivarius (UCC500) or Lactobacillus rhamnosus (GG)

Background: Propionic and butyric acids are important nutrients for the mucosal cells and may therefore increase the nutritional status and reduce the permeability of the colonic mucosa. These acids have also been suggested to counteract diseases in the colon, e.g. ulcerative colitis and colon cancer. Different substrates lead to different amounts and patterns of carboxylic acids (CAs). Objective: To study the effect of probiotics on CA formation in the hindgut of rats given inulin. Design: The rats were given inulin, marketed as highly soluble by the producer, together with the probiotic bacteria Bifidobacterium lactis (Bb-12), Lactobacillus salivarius (UCC500) or Lactobacillus rhamnosus (GG), or a mixture of all three. Results: Rats fed inulin only had comparatively high proportions of propionic and butyric acids throughout the hindgut. When diets were supplemented with Bb-12 and UCC500, the caecal pool of CAs increased compared with inulin only. In the caecum the proportion of butyric acid generally decreased when the rats were fed probiotics. In the distal colon the proportion of propionic and butyric acid was lower, while that of lactic acid was generally higher. The caecal pH in rats fed GG and Bb-12 was lower than expected from the concentration of CAs. Further, rats fed GG had the lowest weight gain and highest caecal tissue weight. Conclusions: It is possible to modify the formation of CAs by combining inulin with probiotics. Different probiotics had different effects

A water-soluble fraction from a by-product of wheat increases the formation of propionic acid in rats compared with diets based on other by-product fractions and oligofructose

Background: Dietary fibre is fermented by the colonic microbiota to carboxylic acids (CA), with potential health effects associated in particular with butyric and propionic acid. Objective: To investigate the formation of CA in the hindgut of healthy rats fed dietary fibre from different fractions of wheat shorts, a by-product of the milling of wheat. Design: Rats were fed dietary fibre (80 g/kg feed per day for 7 days) from wheat shorts and fractions thereof (ethanol-soluble, water-soluble and insoluble fractions), oligofructose (OF) diet and a mixture of oligofructose and raffinose (OR) diet. Results: The water-soluble fraction, with a high content of arabinoxylan (AX), increased the formation of propionic acid in the hindgut and lowered the ratio of acetic to propionic acid in the portal blood of rats. High levels and proportions of butyric acid were seen in rats fed the OR diet. The pattern of CA resulting from the ethanol-soluble diet, mainly composed of fructan and raffinose, was more similar to that of the OF diet than the OR diet. Conclusions: The high formation of propionic acid with the water-soluble fraction may be attributed to the high AX content. The results also indicate that the wheat fructans produced more propionic acid and less butyric acid than oligofructose. It may furthermore be speculated that the increased formation of butyrate with the OR diet was due to synergistic effects of the components in this diet

Contribution of diet to the composition of the human gut microbiota

This paper is part of the Proceedings from the 2013 ENGIHR Conference in Valencia, Spain. More papers from this supplement can be found at http://www.microbecolhealthdis.net Microbial Ecology in Health & Disease 2015. © 2015 Daniela Graf et al. This is an Open Access article distributed under the terms of the Creative Commons Attribution-Noncommercial 3.0 Unported License (http://creativecommons.org/licenses/by-nc/3.0/), permitting all non-commercial use, distribution, and reproduction in any medium, provided the original work is properly cited. ACKNOWLEDGEMENTS The authors acknowledge the support of the European Science Foundation (ESF), in the framework of the Research Networking Programe, The European Network for Gastrointestinal Health Research.Peer reviewedPublisher PD

Blueberry Husks and Probiotics Attenuate Colorectal Inflammation and Oncogenesis, and Liver Injuries in Rats Exposed to Cycling DSS-Treatment.

Long-term colonic inflammation promotes carcinogenesis and histological abnormalities of the liver, and colorectal tumours frequently arise in a background of dysplasia, a precursor of adenomas. Altered colonic microbiota with an increased proportion of bacteria with pro-inflammatory characteristics, have been implicated in neoplastic progression. The composition of the microbiota can be modified by dietary components such as probiotics, polyphenols and dietary fibres. In the present study, the influence of probiotics in combination with blueberry husks on colorectal carcinogenesis and subsequent liver damage was evaluated.Colorectal tumours were induced in rats by cyclic treatment with dextran sulphate sodium (DSS). Blueberry husks and a mixture of three probiotic strains (Bifidobacterium infantis DSM 15159, Lactobacillus gasseri, DSM 16737 and Lactobacillus plantarum DSM 15313) supplemented a basic diet fortified with oats. The condition of the rats was monitored using a disease activity index (DAI). A qualitative and quantitative histological judgement was performed on segments of distal colon and rectum and the caudate lobe of the liver. The formation of short-chain fatty acids, bacterial translocation, the inflammatory reaction and viable count of lactobacilli and Enterobaceriaceae were addressed.Blueberry husks with or without probiotics significantly decreased DAI, and significantly reduced the number of colonic ulcers and dysplastic lesions. With a decreased proportion of blueberry husk in the diet, the probiotic supplement was needed to achieve a significant decrease in numbers of dysplastic lesions. Probiotics decreased faecal viable count of Enterobacteriaceae and increased that of lactobacilli. Blueberry husks with or without probiotics lowered the proportion of butyric acid in distal colon, and decreased the haptoglobin levels. Probiotics mitigated hepatic injuries by decreasing parenchymal infiltration and the incidence of stasis and translocation. The results demonstrate a dietary option for use of blueberry husks and probiotics to delay colonic carcinogenesis and hepatic injuries in the rat model

Colorectal Oncogenesis and Inflammation in a Rat Model Based on Chronic Inflammation due to Cycling DSS Treatments

Inflammation is known to be linked with development of colorectal cancer, and the aim was to assess the malignant potential and degree of inflammation in a dextran-sulphate-sodium-(DSS-) induced cyclic colonic tumour model (CTM) in rats and to compare it with the azoxymethane-(AOM-) induced CTM model. Tumours developed in both groups, although, in the DSS group, the colonic mucosa appeared edematous and the number of haemorrhagic erosions and quantity of dysplastic lesions were higher as well as the mucosal concentration of myeloperoxidase and faecal viable count of Enterobacteriaceae. The livers were affected as evaluated by steatosis, parenchymal loss, haemorrhage, and inflammatory infiltrations, and higher proportions of acetate and lower proportions of butyrate in colonic content were found. The DSS model seems to mimic the clinical situation and may be valuable for investigation of inflammation-related dysplasia and colon cancer, as well as for altered liver function by endogenous inflammatory mediators

Barley products of different fibre composition selectively change microbiota composition in rats

1 ScopeSeveral dietary fiber properties are suggested to be important for the profiling of the microbiota composition, but those characteristics are rather unclear. Whether different physico‐chemical properties of barley dietary fiber influence the gut microbiota composition is investigated.2 Methods and resultsSeven diets containing equal amounts of dietary fiber from barley malts, brewer\u27s spent grain (BSG), and barley extracts, resulting in varying amounts of β‐glucan, soluble arabinoxylan, and insoluble arabinoxylan in the diets were given to conventional rats. Malts increased microbiota alpha diversity more than BSG and the extracts. The intake of soluble arabinoxylan was related to Akkermansia and propionic acid formation in the cecum of rats, whereas β‐glucan and/or insoluble arabinoxylan were attributed to some potentially butyrate‐producing bacteria (e.g., Lactobacillus, Blautia, and Allobaculum).3 ConclusionThis study demonstrates that there is a potential to stimulate butyrate‐ and propionate‐producing bacteria in the cecum of rats with malt products of specific fiber properties. Moreover, BSG, a by product from beer production, added to malt can possibly be used to further modulate the microbiota composition, toward a higher butyric acid formation. A complex mixture of fiber as in the malts is of greater importance for microbiota diversity than purer fiber extracts

Novel xylan degrading enzymes from polysaccharide utilizing loci of Prevotella copri DSM18205

Prevotella copri is a bacterium that can be found in the human gastrointestinal tract (GIT). The role of P. copri in the GIT is unclear, and elevated numbers of the microbe have been reported both in dietary fiber-induced improvement in glucose metabolism but also in conjunction with certain inflammatory conditions. These findings raised our interest in investigating the possibility of P. copri to grow on xylan, and identify the enzyme systems playing a role in digestion of xylan-based dietary fibers. Two xylan degrading polysaccharide utilizing loci (PUL10 and 15) were found in the genome, with three and eight glycoside hydrolase (GH) -encoding genes, respectively. Three of them were successfully produced in Escherichia coli: One extracellular enzyme from GH43 (subfamily 12, in PUL10, 60 kDa) and two enzymes from PUL15, one extracellular GH10 (41 kDa), and one intracellular GH43 (subfamily 137 kDa). Based on our results, we propose that in PUL15, GH10 (1) is an extracellular endo-1,4-β-xylanase, that hydrolazes mainly glucuronosylated xylan polymers to xylooligosaccharides (XOS); while, GH43_1 in the same PUL, is an intracellular β-xylosidase, catalyzing complete hydrolysis of the XOS to xylose. In PUL10, the characterized GH43_12 is an arabinofuranosidase, with a role in degradation of arabinoxylan, catalyzing removal of arabinose-residues on xylan.Fil: Linares Pastén, Javier A. Lund University. Biotechnology Department; SueciaFil: Hero, Johan Sebastian. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Planta Piloto de Procesos Industriales Microbiológicos; ArgentinaFil: Pisa, José Horacio. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Planta Piloto de Procesos Industriales Microbiológicos; ArgentinaFil: Teixeira, Cristina. Lund University. Biotechnology Department; SueciaFil: Nyman, Margareta. Department Food Technology, Engineering And Nutrition; SueciaFil: Adlercreutz, Patrick. Lund University. Biotechnology Department; SueciaFil: Martinez, Maria Alejandra. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Planta Piloto de Procesos Industriales Microbiológicos; ArgentinaFil: Nordberg Karlsson, Eva. Universidad Nacional de Tucumán. Facultad de Ciencias Exactas y Tecnología; Argentin

Formation of Short-Chain Fatty Acids, Excretion of Anthocyanins, and Microbial Diversity in Rats Fed Blackcurrants, Blackberries, and Raspberries

Introduction. Berries contain high amounts of dietary fibre and flavonoids and have been associated with improved metabolic health. The mechanisms are not clear but the formation of SCFAs, especially propionic and butyric acids, could be important. The potent antioxidant and antimicrobial properties of flavonoids could also be a factor, but little is known about their fate in the gastrointestinal tract. Aim. To compare how blackcurrants, blackberries, raspberries, and Lactobacillus plantarum HEAL19 affect formation of SCFAs, inflammatory status, caecal microbial diversity, and flavonoids. Results and Conclusions. Degradation of the dietary fibre, formation of SCFAs including propionic and butyric acids, the weight of the caecal content and tissue, and the faecal wet and dry weight were all higher in rats fed blackcurrants rather than blackberries or raspberries. However, the microbial diversity of the gut microbiota was higher in rats fed raspberries. The high content of soluble fibre in blackcurrants and the high proportion of mannose-containing polymers might explain these effects. Anthocyanins could only be detected in urine of rats fed blackcurrants, and the excretion was lower with HEAL19. No anthocyanins or anthocyanidins were detected in caecal content or blood. This may indicate uptake in the stomach or small intestine