Nowadays, non-communicable diseases (NCDs), which include obesity and cardiometabolic disorders, are responsible for almost 70% of deaths worldwide2. Researchers showed that unhealthy diets and sedentary lifestyles can affect gut microbiome health and diversity, which in turn can contribute to the development of NCDs [3].
Dietary habits
The gut microbiome can temporarily resist external changes, such as antibiotic consumption or dietary variations, to maintain the body in a good physical state. Yet, extreme conditions, such as malnutrition or infections, can disturb the sensitive balance between the body and the microbes. This can lead to disruption of the microbiome, so-called dysbiosis. Dietary habits highly influence the gut microbiota composition, which can lead to obesity as well as mood and anxiety disorders. For example, high fat and low fibre diets negatively impact microbial diversity and weaken the resistance against inflammation and harmful substances. Plant-based and high fibre diets enhance microbial species diversity allowing good microbes to grow and protect the body.
High protein diets
High protein diets are popular in Western societies in the fight against obesity. Although they are effective for weight loss, such diets influence microbiota-derived products in the gut. Ammonia, organic acids, aromatic compounds and other substances may negatively impact the lining of the large intestine [4]. Researchers are cautious about the long-term use of such diets.
Time for more fibre
In contrast with proteins, diets containing high amounts of fibres are known for their benefits on human metabolism. Fibre consumption helps to reduce appetite, enhances digestion, lowers cholesterol and blood sugar and regulates the gut microbiome. Fermentation of prebiotic fibres in the gut by the microbes has a double role. It increases the energy extracted from the diet and produces products, such as short chain fatty acids, that are beneficial for emotional behaviour and energy metabolism [5,7, 8].

Good and bad fats
High fat consumption is widespread due to the extensive use of fats in ready-made and processed foods. High fat diets induce changes on the microbial community structure and functions. In Western societies, behavioural and mood disorders are often related with unhealthy diets and low-activity lifestyles. More recently, mental disorders have also been associated with intestinal dysbiosis. Poor nutrition due to high fat intake increases the risk of anxiety or depression6,7. However, not all fats are the same. Saturated fats, such as tropical oils and dairy fats, reduce microbial diversity and quality, while no negative effect is reported for polyunsaturated fats [5].
Dietary guidelines
With dietary habits influencing human health, it is important for consumers to have sufficient information about food choices and their impact on health. Scientific research can provide evidence-based nutritional recommendations that form the basis of dietary guidelines. These should then be used to communicate the right messages to the consumers and guide them towards healthier food options.
References
1. Gut microbiota’s effect on physical and mental health (MyNewGut) https://www.eufic.org/en/healthy-living/article/gut-microbiotas-effect-on-physical-and-mental-health-mynewgut
2. Major NCD’s and their risk factors http://www.who.int/ncds/introduction/en/
3. Swinburn BA, Sacks G, Hall KD, McPherson K, Finegood DT, Moodie ML, et al. The global obesity pandemic: shaped by global drivers and local environ- ments. Lancet Lond Engl 2011 Aug 27;378(9793):804e14. https://doi.org/ 10.1016/S0140-6736(11)60813-1.
4. Blachier et al. (2018) High-protein diets for weight management: Interactions with the intestinal microbiota and consequences for gut health. A position paper by the MyNewGut study group. Clin Nutr. Sep 20. pii: S0261-5614(18)32454-3. doi: 10.1016/j.clnu.2018.09.016
5. Sanz et al. (2018) Towards microbiome-informed dietary recommendations for promoting metabolic and mental health: Opinion papers of the MyNewGut project. Clin Nutr. December 2018 Volume 37, Issue 6, Part A, Pages 2191–2197 doi: https://doi.org/10.1016/j.clnu.2018.07.007
6. Wolters et al. “Dietary fat, the gut microbiota, and metabolic health – a systematic review conducted within the MyNedwGut project. (Clinical Nutrition, under review)
7. Dinan et al. (2018). Feeding melancholic microbes: MyNewGut recommendations on diet and mood. Clinical Nutrition, https://doi.org/10.1016/j.clnu.2018.11.01
8. Benítez-Paez A, Gomez Del Pulgar Eva María, Kjølbæk Louise, Brahe Lena Kirchner, Astrup Arne, Larsen Lesli Hingstrup, et al. Impact of dietary fiber and fat on gut microbiota re-modeling and metabolic health. Trends Food SciTechnol 2016 Nov;57:201e2012. https://doi.org/10.1016/j.tifs.2016.11.001.
Image Reference:
Mahesh S. Desai,1,2,3,*§ Anna M. Seekatz,2 Nicole M. Koropatkin,2 Nobuhiko Kamada,2 Christina A. Hickey,4Mathis Wolter,3 Nicholas A. Pudlo,2 Sho Kitamoto,2 Nicolas Terrapon,5 Arnaud Muller,6 Vincent B. Young,2Bernard Henrissat,5 Paul Wilmes,1 Thaddeus S. Stappenbeck,4 Gabriel Núñez,2 and Eric C. Martens2,*,7
“A dietary fiber-deprived gut microbiota degrades the colonic mucus barrier and enhances pathogen susceptibility”
Cell. 2016 Nov 17; 167(5): 1339–1353