Glen R. Gibson

Influence of mode of delivery on gut microbiota composition in seven year old children.

Intestinal microbiota development begins immediately following birth.1 The composition of the infant’s evolving microbiota is initially defined by the mother, the source of the newborn’s first microbial inoculum. Colonising bacteria rapidly adapt to breast milk and epithelial mucins as sources of nutrients. The prevalence of caesarean section delivery in Western countries is increasing. Caesarean born babies are deprived of contact with the maternal/vaginal microbiota and the first exposure is characterised by a lack of strict anaerobes and the presence of facultative anaerobes such as Clostridium species.2 Caesarean born infants have a more slowly diversifying microbiota, with differences reported from normally born infants, even after six months of age. Aberrancies in early microbiota acquisition can affect immunophysiological development with a heightened disease risk.2,3 This …

Effects of targeted delivery of propionate to the human colon on appetite regulation, body weight maintenance and adiposity in overweight adults.

Objective The colonic microbiota ferment dietary fibres, producing short chain fatty acids. Recent evidence suggests that the short chain fatty acid propionate may play an important role in appetite regulation. We hypothesised that colonic delivery of propionate would increase peptide YY (PYY) and glucagon like peptide-1 (GLP-1) secretion in humans, and reduce energy intake and weight gain in overweight adults. Design To investigate whether propionate promotes PYY and GLP-1 secretion, a primary cultured human colonic cell model was developed. To deliver propionate specifically to the colon, we developed a novel inulin-propionate ester. An acute randomised, controlled cross-over study was used to assess the effects of this inulin-propionate ester on energy intake and plasma PYY and GLP-1 concentrations. The long-term effects of inulin-propionate ester on weight gain were subsequently assessed in a randomised, controlled 24-week study involving 60 overweight adults. Results Propionate significantly stimulated the release of PYY and GLP-1 from human colonic cells. Acute ingestion of 10 g inulin-propionate ester significantly increased postprandial plasma PYY and GLP-1 and reduced energy intake. Over 24 weeks, 10 g/day inulin-propionate ester supplementation significantly reduced weight gain, intra-abdominal adipose tissue distribution, intrahepatocellular lipid content and prevented the deterioration in insulin sensitivity observed in the inulin-control group. Conclusions These data demonstrate for the first time that increasing colonic propionate prevents weight gain in overweight adult humans. Trial registration number NCT00750438.

Health benefits of probiotics: are mixtures more effective than single strains?

PurposeMost studies on probiotics utilise single strains, sometimes incorporated into yoghurts. There are fewer studies on efficacy of mixtures of probiotic strains. This review examines the evidence that (a) probiotic mixtures are beneficial for a range of health-related outcomes and (b) mixtures are more or less effective than their component strains administered separately.ResultsMixtures of probiotics had beneficial effects on the end points including irritable bowel syndrome and gut function, diarrhoea, atopic disease, immune function and respiratory tract infections, gut microbiota modulation, inflammatory bowel disease and treatment of Helicobacter pylori infection. However, only 16 studies compared the effect of a mixture with that of its component strains separately, although in 12 cases (75%), the mixture was more effective.ConclusionProbiotic mixtures appear to be effective against a wide range of end points. Based on a limited number of studies, multi-strain probiotics appear to show greater efficacy than single strains, including strains that are components of the mixtures themselves. However, whether this is due to synergistic interactions between strains or a consequence of the higher probiotic dose used in some studies is at present unclear.

Isolation and characterization of human colonic bacteria able to hydrolyse chlorogenic acid

D. COUTEAU, A.L. McCARTNEY, G.R. GIBSON, G. WILLIAMSON AND C.B. FAULDS. 2001.

Fermentable Carbohydrate Alters Hypothalamic Neuronal Activity and Protects Against the Obesogenic Environment

Obesity has become a major global health problem. Recently, attention has focused on the benefits of fermentable carbohydrates on modulating metabolism. Here, we take a system approach to investigate the physiological effects of supplementation with oligofructose‐enriched inulin (In). We hypothesize that supplementation with this fermentable carbohydrate will not only lead to changes in body weight and composition, but also to modulation in neuronal activation in the hypothalamus. Male C57BL/6 mice were maintained on a normal chow diet (control) or a high fat (HF) diet supplemented with either oligofructose‐enriched In or corn starch (Cs) for 9 weeks. Compared to HF+Cs diet, In supplementation led to significant reduction in average daily weight gain (mean ± s.e.m.: 0.19 ± 0.01 g vs. 0.26 ± 0.02 g, P < 0.01), total body adiposity (24.9 ± 1.2% vs. 30.7 ± 1.4%, P < 0.01), and lowered liver fat content (11.7 ± 1.7% vs. 23.8 ± 3.4%, P < 0.01). Significant changes were also observed in fecal bacterial distribution, with increases in both Bifidobacteria and Lactobacillius and a significant increase in short chain fatty acids (SCFA). Using manganese‐enhanced MRI (MEMRI), we observed a significant increase in neuronal activation within the arcuate nucleus (ARC) of animals that received In supplementation compared to those fed HF+Cs diet. In conclusion, we have demonstrated for the first time, in the same animal, a wide range of beneficial metabolic effects following supplementation of a HF diet with oligofructose‐enriched In, as well as significant changes in hypothalamic neuronal activity.

Gastrointestinal Microflora: Probiotics

Publisher Summary Probiotics have long been recognized as health-promoting agents. Advances in molecular methodologies and conduction of well-designed studies performed in the past two decades illustrate the potential of probiotics against a multitude of conditions. Probiotic is a preparation or a product containing viable, defined microorganisms in sufficient numbers that alter the microflora in a compartment of the host and by that exert beneficial health effects in this host.The human adult colon is the most complex bacterial ecosystem in the human body, harboring more than 400 different culturable bacterial species belonging to more than 50 different genera. The human gut, site of numerous diseases acute and chronic, also plays an important role in health promotion through the activities of the resident microflora. Humans have been consuming live bacterial cultures for centuries in the form of fermented milk without any knowledge of the active ingredients or how they work. Among the first reported probiotic intakes was the ingestion of soured milk by nomads over 2000 years ago.

In vitro measurement of the impact of human milk oligosaccharides on the faecal microbiota of weaned formula‐fed infants compared to a mixture of prebiotic fructooligosaccharides and galactooligosaccharides

Aims:  To investigate the impact of human milk oligosaccharides (HMOs) from a single donor (SO), HMOs from multiple donors (PO), a fructooligosaccharides and galactooligosaccharides mixture (FG) on the composition of a batch culture inoculated with faecal microbiota from formula‐fed infants.

Investigation of the faecal microbiota of geriatric cats

Aims:  Aim of the study was to investigate the faecal microbiota of geriatric cats, as aging affects the nutrient digestibility and metabolic function of the feline intestine.

Isolation of culturable yeasts from market wines and evaluation of the 5.8S-ITS rDNA sequence analysis for identification purposes.

Aims:  To test the possibility that wines available in the marketplace may contain culturable yeasts and to evaluate the 5·8S‐ITS rDNA sequence analysis as adequate means for the identification of isolates.

Functional foods for the gut: probiotics, prebiotics and synbiotics

Abstract: The human large intestine is an intensively colonised area containing bacteria that are health positive, as well as pathogenic. Probiotics have a long history of use in humans as live microbial feed additions. In contrast, a prebiotic is a non digestible food ingredient that beneficially affects the host by targeting indigenous components thought to be positive. Main prebiotic targets at the moment are bifidobacteria and lactobacilli (although this may change as our knowledge of the flora diversity and functionality expands). Any dietary component that reaches the colon intact is a potential prebiotic, however much of the interest in the development of prebiotics is aimed at non-digestible oligosaccharides. For prebiotics (and probiotics) a determination of the health consequences that are associated with gut flora modulation (e.g. anti-pathogen activities, reduced inflammatory disorders, immunological effects, protective aspects for bowel cancer, neutralisation of certain toxins) is needed and research is ongoing.