Table 1.

Influence of various types of dietary components on gut microbiome and associated physiological changes.

Dietary component	Effect on gut bacteria	Metabolic changes by gut bacteria	Effects on health (Lung diseases which are associated with dietary intake have been highlighted in bold-italic font)	References (PMIDs)
PROTEINS
Plant proteins (Whey and pea protein)	Increased Lactobacillus and Bifidobacteria Reduced pathogenic Bacteroides fragilis and Clostridium perfringens	Increased SCFA levels	Anti-inflammatory Maintenance of mucosal barrier Increased Tregs	29311977 26463271 21276631
Animal proteins	Increased Bacteroides and Alistipes	Reduced SCFA levels	Increased inflammatory disorders High risk of Inflammatory Bowel Disease (IBD) Increased levels of proatherogenictrimethylamine-N-oxide (TMAO) increases risk of cardiovascular disease (CVD)	29311977 29534465 20679230 22055893 28388917
High protein/carbohydrate ratio	Reduced Roseburia and Eubacterium	Less fecal butyrate	Increased inflammation	21389180 29534465
CARBOHYDRATES
Digestible carbohydrates (lactose)	Increased Bifidobacteria Lactose leads to high Lactobacillus Lactose high SCFA production	Increased SCFA levels	Anti-inflammatory	22435727 28388917 22435727
Non-digestible carbohydrates (Wheat bran)	Increased Bifidobacteria and Lactobacillus	Increased SCFA levels	Increased inflammatory disorders	26636660 29416529
Non-digestible carbohydrates: Dietary Fiber (DF), Resistant starch (RS) and whole grain barley	Increased Roseburia, Ruminococcus and Eubacterium	Increased fecal butyrate	Reduced inflammation DF shows beneficial effects in Asthma, Cystic fibrosis, COPD	29042495 24440361 18063592
Non-digestible carbohydrates Fructooligosaccharides (FOS), Galactooligosaccharides (GOS) and polydextrose	Increased Roseburia, and Eubacterium Reduced Enterococcus and Clostridia	Increased fecal butyrate	Reduced inflammatory response GOS alleviated asthma and eosinophillia in murine models	23951074 25849971 27523186
FATS
Saturated fat (lard fat)	Decreased Bifidobacteria and Eubacterium species	Reduced SCFA levels	Increased inflammatory disorders Asthma with high fat low carbohydrate diet Control metabolic endotoxemia-induced inflammation TLR activation, Adipose tissue inflammation (obesity), insulin resistance (Diabetes) Increases risk of cardiovascular disease	26321659 28804483 28388917
Unsaturated fat (fish oil)	Increased Roseburia, Ruminococcus and Eubacterium	Increased fecal butyrate	Reduced inflammation Omega-3 fatty acids ameliorate asthma, pneumonia and COPD	28388917 26784651 28951525 29215589
SPECIFIC DIET REGIMES
Western: High in animal protein and saturated and trans fat, Low in fiber	Decreased Bifidobacteria and Eubacterium species	Reduced SCFA levels	Increased inflammatory disorders Studies on asthma patients show mixed outcomes	29276171 26011307 28388917
Gluten free	Increased Roseburia, Ruminococcus and Eubacterium	Increased fecal butyrate	Reduced inflammation	27102333 25651995
Mediterranean: Beneficial mono-unsaturated and poly-unsaturated fatty acids, high levels of polyphenols and other antioxidants, high fiber and low glycemic carbohydrates, more vegetables less animal protein	Increases in Lactobacillus, Bifidobacterium, and Prevotella Decreases in Clostridium	Higher SCFA levels	Reduced inflammatory response Less adherence to Mediterranean diet associated with increase in TMAO and therefore, CVD Less adherence to Mediterranean diet associated diabetes and obesity	28789729 24987952 26416813