Effect of dairy based food ingredients on the gut microbiota of older consumers

Abstract

The proportion of the world population aged over 60 yrs is steadily increasing. Non-communicable disease and cognitive decline are prevalent in the elderly population which present a significant burden for national health care systems and economies. Malnutrition is prevalent in many longterm care unit-residing older people and importantly, it is also common among community-living elderly people. The deficiency in the aged population in certain nutrients, such as vitamins and proteins, may be associated with dementia and loss of bone and muscular health. Importantly, frailty that is accompanied by sarcopenia (i.e. deregulation of muscular homeostasis) is prevalent among older adults and may gradually lead to functional disability. Many studies have shown the importance of dietary management of aged-related conditions. In the last decade, our knowledge of the importance of the gut microbiota in health and disease has significantly increased. Importantly, shifts in the composition and diversity of the gut microbiota of older people compared to healthy young adults are being identified and associated with ageing and age-related conditions, such as frailty. Similarly to other conditions for which gut microbiota modulation may lead to significant improvement of health, microbiota modulation may be a novel strategy for preventing or ameliorating ageing. This proposed gut microbiota modulation could be achieved through the use of prebiotics, probiotics or live bacteriotherapy among others. Importantly, diet can be a means of general (not targeted) gut microbiota modulation due to its documented significance in the shaping of the gut microbiota and to the fact that common dietary components may be a source of novel prebiotics. In the ElderFood project, we investigated the prebiotic potential of milk and milk derived components to modulate the gut microbiota of older subjects. Using in vitro and in vivo colon models, we generated an in-depth insight into the effect of glycomacropeptide (GMP), a milk-derived peptide that contains mucin-type glycans, and milk (whole and lactose free) on the elderly gut microbiota. We also performed exploratory work for the investigation of fibre and polyphenol-rich foods on the elderly gut microbiota and on artificial bacterial communities. The use of artificial bacterial communities can increase our understanding of the microbiota dynamics and how microbiota members respond to diet.