Swapping White for High-Fibre Bread Increases Faecal Abundance of Short-Chain Fatty Acid-Producing Bacteria and Microbiome Diversity: A Randomized, Controlled, Decentralized Trial.

A low-fibre diet leads to gut microbiota imbalance, characterized by low diversity and reduced ability to produce beneficial metabolites, such as short-chain fatty acids (SCFAs). This imbalance is associated with poor gastrointestinal and metabolic health. We aimed to determine whether one dietary change, substitution of white bread with high-fibre bread, improves gut microbiota diversity and SCFA-producing capability. Twenty-two healthy adults completed a two-phase randomized, cross-over trial. The participants consumed three slices of a high-fibre bread (Prebiotic Cape Seed Loaf with BARLEYmax®) or control white bread as part of their usual diet for 2 weeks, with the treatment periods separated by a 4-week washout. High-fibre bread consumption increased total dietary fibre intake to 40 g/d, which was double the amount of fibre consumed at baseline or during the white bread intervention. Compared to white bread, the high-fibre bread intervention resulted in higher faecal alpha diversity (Shannon, p = 0.014) and relative abundance of the Lachnospiracae ND3007 group (p < 0.001, FDR = 0.019) and tended to increase the butyrate-producing capability (p = 0.062). In conclusion, substituting white bread with a high-fibre bread improved the diversity of gut microbiota and specific microbes involved in SCFA production and may enhance the butyrate-producing capability of gut microbiota in healthy adults. These findings suggest that a single dietary change involving high-fibre bread provides a practical way for adults to exceed recommended dietary fibre intake levels that improve gut microbiota composition and support gastrointestinal and metabolic health.

Assessing the Effect of Plant-Based Mince on Fullness and Post-Prandial Satiety in Healthy Male Subjects.

This study aimed to assess the effect of substituting plant-based mince for beef mince in a standard pasta meal on the amount consumed and on objective and subjective measures of post-prandial satiety. Healthy, adult males (n = 24) consumed a pasta lunch meal containing either plant-based or beef mince at separate visits, and the amount consumed measured at each visit. Perceptions of hunger, fullness and satisfaction were recorded and blood samples collected before and for 3 h after eating, when a buffet meal was provided. Participants consumed 586 kJ less of the pasta meal prepared with plant-based mince compared to beef mince (p < 0.05). Energy intake at the buffet meal and measures of fullness, satiety and satisfaction after the pasta meal were not different between plant and beef mince (p > 0.05). Post-prandial Glucagon-Like Peptide-1 (GLP-1), but not insulin or leptin concentrations, were lower after the plant-based pasta meal (p < 0.05). Our results suggest that the pasta meal containing plant-based mince was more satiating than an equivalent meal prepared with beef mince, and that this was not associated with greater energy intake at a subsequent meal occasion. Further studies that evaluate the longer-term effects of replacing meat with plant-based mince on energy intakes and explore the mechanisms underlying the lower consumption of the plant-based mince meal would be valuable.

Substitution of Refined Conventional Wheat Flour with Wheat High in Resistant Starch Modulates the Intestinal Microbiota and Fecal Metabolites in Healthy Adults: A Randomized, Controlled Trial.

BACKGROUND: Resistant starch (RS) confers many health benefits, mostly through the microbial production of SCFAs, but foods containing appreciable RS are limited. High-amylose wheat (HAW) is high in RS and lowers the glycemic response of foods, but whether it can improve gastrointestinal health measures is unknown. OBJECTIVES: The objective of this study was to determine whether daily consumption of HAW food products improved markers of gastrointestinal health in healthy men and women compared with similar foods made from conventional wheat. METHODS: Eighty healthy adults (47 women and 33 men) were enrolled in a 4-arm parallel, randomized-controlled, double-blind trial. After a 2-wk low-dietary fiber run-in period, they were randomly allocated to 1 of 4 treatment groups: low-amylose wheat (LAW)-refined (LAW-R), LAW-wholemeal (LAW-W), HAW-refined (HAW-R), and HAW-wholemeal (HAW-W) and consumed the assigned test bread (160 g/d) and biscuits (75 g/d) for 4 wk. Fecal biochemical markers were measured at baseline and 4 wk. Microbial abundance and diversity were quantified using 16S ribosomal RNA sequencing and perceived gut comfort by a semiquantitative questionnaire completed at baseline, 2 wk, and 4 wk. RESULTS: HAW showed similar effects on fecal output and excretion of total SCFA compared with LAW, but changes were observed in secondary measures for the refined treatment groups. At 4 wk, the HAW-R group had 38% higher fecal butyrate excretion than the LAW-R group (P < 0.05), and higher fecal SCFA-producing bacteria, Roseburia inulinivorans (P < 0.001), than at baseline. In comparison with baseline, LAW-R increased fecal p-cresol concentration, and fecal abundance of a p-cresol-producing bacterium, Clostridium from the Peptostreptococcaceae family, but both were reduced by HAW-R. Amylose level did not affect measures of fecal consistency or adversely affecting digestive comfort. CONCLUSIONS: Increasing RS intake of healthy adults by substituting refined conventional wheat with refined HAW modulates fecal metabolites and microbes associated with gastrointestinal health.This trial was registered at anzctr.org.au as ACTRN12618001060235.

Alcoholic beverage intake throughout the week and contribution to dietary energy intake in Australian adults.

OBJECTIVE: To assess alcoholic beverage intake among Australian adults and its contribution to dietary energy intake. DESIGN: Secondary analysis of a national dietary survey using 24 h dietary recall. SETTING: Australian National Nutrition and Physical Activity Survey (NNPAS) conducted from May 2011 to June 2012. SUBJECTS: Adults (n 9341) aged 19 years and over. RESULTS: On the day preceding the survey, 32·8% of Australian adults consumed one or more alcoholic drinks. The median contribution to total energy intake for consumers did not differ significantly between males and females (13·7% and 12·9%, respectively; P=0·10). The prevalence of consumption of alcoholic drinks on Friday, Saturday and Sunday was 38·8 (95% CI 37·1, 40·5)%, higher than the other days (28·6 (95% CI 27·5, 29·8)%). Consumers had a median daily intake of 4·0 standard drinks on the weekend compared with 3·0 standard drinks during the week (P<0·001). Beer was the most commonly consumed alcoholic beverage for men and white wine for women. The highest prevalence of alcoholic beverage intake occurred in the highest quintile of adjusted household income (42·7 (95% CI 40·4, 45·0)%) and the 'overweight' BMI category (40·3 (95% CI 38·5, 42·0)%). Alcoholic beverage intake among consumers was significantly different by household income quintile (median 3·84 (highest) v. 3·05 standard drinks (lowest); P<0·05) and by waist circumference category (median 4·09 standard drinks (highest)). CONCLUSIONS: Alcoholic drinks contribute substantially to the dietary energy intake of Australian adults. The type and pattern of consumption of alcoholic beverage intake should be considered in the development of strategies to improve dietary intake.