When asked, what is the best diet to follow, there is normally a wide range of options provided. These are mostly based on contemporary patterns, ethical, religious, geographical and preference. However, whilst all dietary practices have aspects that are lauded over, one style of eating consistently supports general benefit to the consumer. That is the traditional Mediterranean diet (MD), defined as: A nutritionally recommended dietary pattern characterised by high-level intake of fruit, vegetables, legumes, nuts and minimally processed cereals, moderately high consumption of ﬁsh, low intake of saturated fat, meat and dairy products and regular, but moderate, consumption of alcohol. Unesco has recognised the Mediterranean diet (MD) as an intangible cultural heritage.
The MD is a pronounced, but not exclusively vegetarian-oriented dietary style, which has been demonstrated to be beneﬁcial for the treatment of obesity, type 2 diabetes, inﬂammatory diseases and cardiovascular diseases.
A paper published in the gastroenterology journal GUT in Sept 2016, explored in further details the effect of consuming a predominately MD style diet against more omnivore diets to see what effect it had on the microbiome composition and metabolic output.
Habitual diet plays a major role in shaping the composition of the gut microbiota, and determines the repertoire of microbial metabolites that can influence the host. The typical Western diet corresponds to that of an omnivore; however, the Mediterranean diet (MD), common in the Western Mediterranean culture, is to date a nutritionally recommended dietary pattern that includes high-level consumption of cereals, fruit, vegetables and legumes. To investigate the potential benefits of the MD in this cross-sectional survey, we assessed the gut microbiota and metabolome in a cohort of Italian individuals in relation to their habitual diets.
Design and Results
We retrieved daily dietary information and assessed gut microbiota and metabolome in 153 individuals habitually following omnivore, vegetarian or vegan diets. The majority of vegan and vegetarian subjects and 30% of omnivore subjects had a high adherence to the MD. We were able to stratify individuals according to both diet type and adherence to the MD on the basis of their dietary patterns and associated microbiota. We detected significant associations between consumption of vegetable-based diets and increased levels of faecal short-chain fatty acids, Prevotella and some fibre-degrading Firmicutes, whose role in human gut warrants further research. Conversely, we detected higher urinary trimethylamine oxide levels in individuals with lower adherence to the MD.
High-level consumption of plant foodstuffs consistent with an MD is associated with beneficial microbiome-related metabolomic profiles in subjects ostensibly consuming a Western diet.
As our understanding of the consequence of eating not for one, but for trillions grows, the role of the metabolic compounds derived from the bacterial fermentation of different fibres or from foods containing meat derived proteins become increasingly clear.
We as functional superorganisms tend to better value the SCFAS derived from fibre breakdown, but that fibre should be from a wide variety of foods and should be around 30gms per day, a large input missed by many, the costs of which are local and systemic.
 De Filippis F, Pellegrini N, Vannini L, Jeffery IB, La Storia A, Laghi L, Serrazanetti DI, Di Cagno R, Ferrocino I, Lazzi C, Turroni S, Cocolin L, Brigidi P, Neviani E, Gobbetti M, O’Toole PW, Ercolini D. High-level adherence to a Mediterranean diet beneficially impacts the gut microbiota and associated metabolome. Gut. 2015 Sep 28. pii: gutjnl-2015-309957 View Abstract