Table 1.

Effects of bacteria on taste.

Microbes	Effect on Taste	Potential Mechanism	Reference
Staphylococci, Streptococci	Dampen sweet, salty, sour, and bitter tastes	Physical barrier through microbial tongue film	[26]
Streptococcus, Actinomyces, Lactobacillus		Degrade carbohydrates into organic acids	[31]
Prevotella, Porphyromonas		Degrade protein to amino acids and SCFAs	[31]
Streptococci	Alter sweet taste sensitivity	Degrade carbohydrate to lactate	[32]
Lactobacilli	Decrease sour taste sensitivity	Bacterial products raise sour detection thresholds	[33]
Actinobacteria and Bacteroidetes	Increase taste sensitivity, especially bitter	Bacteria produce secondary metabolites that act as precursors of some bitter acids	[27]
Actinomyces, Oribacterium, Solobacterium, Catonella, Campylobacter	Associated with high responsiveness to bitter		[36]
Clostridia	Associated with protein/fat-rich diets and negatively associated with fiber intake		[42]
Proteobacteria, Prevotella	Associated with vegetable-rich diets		[42]
Bacteroidetes, Bacterolidia	Associated with decreased perception of all tastes in obese children		[43]
Streptococci Mutans	Decreased sensitivity for bitter taste and increased risk of dental caries		[44]
Germ Free mice	High preference for sweet taste	Increased number of sweet taste receptors in proximal intestine	[3]
Germ Free mice	Increased preference for fat	Changes in lingual and intestinal fatty acid receptors; increased lipid consumption and decreased post-ingestive feedback satiety signals	[45]