Microbiota and Metabolite Modifications after Dietary Exclusion of Dairy Products and Reduced Consumption of Fermented Food in Young and Older Men.

The gut microbiota adapts to age-related changes in host physiology but is also affected by environmental stimuli, like diet. As a source of both pre- and probiotics, dairy and fermented foods modulate the gut microbiota composition, which makes them interesting food groups to use for the investigation of interactions between diet and ageing. Here we present the effects of excluding dairy products and limiting fermented food consumption for 19 days on gut microbiota composition and circulating metabolites of 28 healthy, young (YA) and older (OA) adult men. The intervention affected gut microbial composition in both groups, with significant increases in Akkermansia muciniphila and decreases in bacteria of the Clostridiales order. Lower fasting levels of glucose and insulin, as well as dairy-associated metabolites like lactose and pentadecanoic acid, were observed after the intervention, with no effect of age. The intervention also decreased HDL and LDL cholesterol levels. Dairy fat intake was positively associated with the HDL cholesterol changes but not with the LDL/HDL ratio. In conclusion, restricting the intake of dairy and fermented foods in men modified their gut microbiota and blood metabolites, while the impact of the dietary restrictions on these outcomes was more marked than the effect of age.

Reprint of: A parallel randomized trial on the effect of a healthful diet on inflammageing and its consequences in European elderly people: design of the NU-AGE dietary intervention study.

BACKGROUND: The proportion of European elderly is expected to increase to 30% in 2060. Combining dietary components may modulate many processes involved in ageing. So, it is likely that a healthful diet approach might have greater favourable impact on age-related decline than individual dietary components. This paper describes the design of a healthful diet intervention on inflammageing and its consequences in the elderly. METHODS: The NU-AGE study is a parallel randomized one-year trial in 1250 apparently healthy, independently living European participants aged 65-80 years. Participants are randomised into either the diet group or control group. Participants in the diet group received dietary advice aimed at meeting the nutritional requirements of the ageing population. Special attention was paid to nutrients that may be inadequate or limiting in diets of elderly, such as vitamin D, vitamin B12, and calcium. C-reactive protein is measured as primary outcome. DISCUSSION: The NU-AGE study is the first dietary intervention investigating the effect of a healthful diet providing targeted nutritional recommendations for optimal health and quality of life in apparently healthy European elderly. Results of this intervention will provide evidence on the effect of a healthful diet on the prevention of age related decline.

A parallel randomized trial on the effect of a healthful diet on inflammageing and its consequences in European elderly people: design of the NU-AGE dietary intervention study.

BACKGROUND: The proportion of European elderly is expected to increase to 30% in 2060. Combining dietary components may modulate many processes involved in ageing. So, it is likely that a healthful diet approach might have greater favourable impact on age-related decline than individual dietary components. This paper describes the design of a healthful diet intervention on inflammageing and its consequences in the elderly. METHODS: The NU-AGE study is a parallel randomized one-year trial in 1250 apparently healthy, independently living European participants aged 65-80 years. Participants are randomised into either the diet group or control group. Participants in the diet group received dietary advice aimed at meeting the nutritional requirements of the ageing population. Special attention was paid to nutrients that may be inadequate or limiting in diets of elderly, such as vitamin D, vitamin B12, and calcium. C-reactive protein is measured as primary outcome. DISCUSSION: The NU-AGE study is the first dietary intervention investigating the effect of a healthful diet providing targeted nutritional recommendations for optimal health and quality of life in apparently healthy European elderly. Results of this intervention will provide evidence on the effect of a healthful diet on the prevention of age related decline.