The study, published in Applied and Environmental Microbiology, found that people fed a beta-glucan-enriched pasta for two months showed increased populations of beneficial bacteria in their intestinal tracts, and reduced populations of non-beneficial bacteria. They also showed reduced LDL (bad) cholesterol.
Led by researchers from the University of Bari, the study is part of a broad effort to identify potential prebiotics that encourage the growth of health-promoting bacteria in the gastrointestinal tract.
The team noted that beta-glucans are fibres – which have been shown to be beneficial for high cholesterol as well as having a number of other potential benefits.
As a result, the Italian authors tested the theory that by feeding study subjects a beta-glucan-enriched pasta, they could modify the species composition of the gut bacteria – possibly leading to improved human health, said study co-author Professor Maria De Angelis.
"These results highlight the influence of fibres and of the Mediterranean diet on gut microbiota, and indirectly on human health," said De Angelis.
In the study, De Angelis and colleagues took faecal and blood samples before and after the study subjects spent two months on diet that included beta-glucan-enriched pasta.
The daily dose of pasta, 100 grams, contained 3 grams of barley beta-glucans – the recommended daily dose in the US and in Europe.
At the study's end, assays of the faecal samples showed a notable increase in potentially beneficial Lactobacilli, and a reduction in Enterobacteriaceae, and other non-beneficial bacteria in subjects' gastrointestinal tracts.
The investigators also discovered an unanticipated rise in the concentration of certain short chain fatty acids, 2-methyl-propanoic, acetic, butyric, and propionic acids, bacterial metabolites, for which there is evidence of anti-inflammatory activity.
From the blood samples, the investigators determined that the average LDL cholesterol among the study subjects had fallen from 107.4 to 93.8 MG/DL.
The beta-glucan-enriched pasta made from a mixture of 75% durum wheat flour and 25% whole grain barley flour.