Microbiology of the human intestinal tract and approaches for its dietary modulation

Gut bacteria can be categorised as being either beneficial or potentially pathogenic due to their metabolic activities and fermentation end-products. Health-promoting effects of the microflora may include immunostimulation, improved digestion and absorption, vitamin synthesis, inhibition of the growth of potential pathogens and lowering of gas distension. Detrimental effects are carcinogen production, intestinal putrefaction, toxin production, diarrhoea/constipation and intestinal infections. Certain indigenous bacteria such as bifidobacteria and lactobacilli are considered to be examples of health-promoting constituents of the microflora. They may aid digestion of lactose in lactose-intolerant individuals, reduce diarrhoea, help resist infections and assist in inflammatory conditions. Probiotics, prebiotics and synbiotics are functional foods that fortify the lactate producing microflora of the human or animal gut.

How different are GM food accepters and rejecters really? A means-end chains application to yogurt in Germany

The purpose of the paper is to identify and describe differences in cognitive structures between consumer segments with differing levels of acceptance of genetically modified (GM) food. Among a sample of 60 mothers three segments are distinguished with respect to purchase intentions for GM yogurt: non-buyers, maybe-buyers and likely-buyers. A homogeneity test for the elicited laddering data suggests merging maybe- and likely-buyers, yielding two segments termed accepters and rejecters. Still, overlap between the segments’ cognitive structures is considerable, in particular with respect to a health focus in the evaluation of perceived consequences and ambivalence in technology assessment. Distinct differences are found in the assessment of benefits offered by GM food and the importance of values driving product evaluation and thus purchase decisions.

Increased whole grain consumption does not affect blood biochemistry, body composition or gut microbiology in healthy low habitual whole grain consumers

Background Whole grain (WG) foods have been suggested to reduce the risk of cardiovascular disease, but studies are inconsistent and effects on cardiovascular risk markers are not clear. Objective The objective of this study was to assess the impact of increasing WG consumption to at least 80 g/d on overall dietary intake, body composition, blood pressure (BP), blood lipids, blood glucose, gastrointestinal microbiology and gastrointestinal symptoms in healthy, middle-age adults with habitual WG intake < 24 g/d. The trial was registered as ISRCTN36521837. Methods Eligible subjects (12 men, 21 women, aged 40-65 y and BMI 20-35 kg/m2) were identified using food frequency questionnaires and subsequently completed 3-day food diaries (3DFD) to confirm habitual WG consumption. Subjects consumed diets high in WG (> 80 g/d) or low in WG (< 16 g/d, refined grain [RG] diet) in a crossover study, with 6-week intervention periods, separated by a 4-week washout. Adherence was achieved by specific dietary advice and provision of a range of cereal food products. The 3DFD, diet compliance diaries and plasma alkylresorcinols (ARs) were used to verify compliance. Results On the WG intervention, consumption increased from 28 g/d to 168 g/d (P < 0.001), accompanied by an increase in plasma ARs (P < 0.001) and total fiber intake (P < 0.001), without any effect on energy or other macronutrients. While there were no effects on studied parameters, there were trends towards increased 24 h fecal weight (P = 0.08) and reduction in body weight (P = 0.10) and BMI (P = 0.08) during the WG compared to the RG period. Conclusion A combination of dietary advice and provision of commercially available food items enabled subjects with a low-moderate habitual consumption of WG to substantially increase their WG intake, but there was little effect on blood biochemical parameters, body composition, BP, fecal measurements or gut microbiology.