Table 4.

Effect of dietary resistant starches on aging-associated gut microbiota and health outcomes.

RS Type	RS Source	Cohort	State of Cohort	Age	Dose (g/d)	Duration of Study	Key Shifts in Gut Microbiota	Outcome	References
RS2	MSPrebiotic from potato	Human	Healthy	Elderly (>70 years) Mid-age (30–50 years)	30 g/d	12 weeks	Phylum ↓ Proteobacteria Genus ↑ Bifidobacteria ↑ Prevotella (only in elderly) ↑ Alistipes (only in elderly) Species ↑ Ruminococcus bromii (only in mid-age)	Marginal increase in butyrate level in elderly	[116]
RS2	MSPrebiotic from potato	Human	Healthy	Elderly (>70 years) Mid-age (30–50 years)	30 g/d	12 weeks		Reduced blood glucose levels and insulin resistance in elderly	[118]
RS2	High-amylose maize	Mice (C57BL/6J male)	Healthy	18–20 mo	18–36% RS	10 weeks	Phylum ↑ Bacteroidetes ↓ Firmicutes Family ↑ Lachnospiraceae ↑ Ruminococceae Genus ↑ Bifidobacterium, ↑ Akkermansia ↑ Allobaculum ↓ Alistipes ↓ Parabacteroides	Increased proglucagon gene expression No significant effect on PYY expression Increase in cecal (empty and full) and entire gastrointestinal tract weights	[117]
RS2	High amylose maize starch with 56% RS2	Mice (C57BL/6 female)	HFD feeding	18 mo	HFD + 20% RS2	16 weeks	Phylum ↓ Proteobacteria Genus ↑ Ruminococcaceae ↑ Lachnospiracea ↓ Desulfovibrio ↓ Ruminiclostridium 9 ↓ Lachnoclostridium ↓ Helicobacter ↓ Oscillibacter ↓ Alistipes ↓ Peptococcus ↓ Rikenella ↓ Marvinbryantia ↓ Parabacteroides	Decreased abundance of pathogen taxa Reversed weight gain and hepatic steatosis and inflammation Increased intestinal permeability Decreased serum and fecal LPS, hepatic IL-4, and colonic IL-2 expression Increased expression of colonic mucin 2 High butyric acid levels and low isobutyric and isovaleric acid levels	[25]
RS2	Acorn and sago	Mice (C57BL/6J male)	HFD induced obesity	8–10 weeks	HFD + 5% RS	8 weeks	Phylum ↑ Bacteroidetes ↓ Firmicutes Genus ↑ S24_7 ↓ Oscillospira ↓ Desulfovibri ↓ Bilophila	Ameliorate HFD-induced glucose intolerance and insulin resistance Increase in SCFAs levels Decrease in leaky gut and inflammation	[26]
RS2	High-amylose maize	Mice (C57BL/6J male)	Healthy	18–20 mo	18–36% RS	10 weeks	-	No effect on body weight and body composition Increased cecum weights Increased expression of cecal proglucagon and PYY mRNA No significant difference in soluble cytokine receptors (sVEGFR1, sTNF-Rb, sIL-4R, sRAGE and sIL- 2Ra) and TNFa expression (gene and protein) in visceral fat	[119]
RS2 + RS3	Corn (having low starch gelatinzation and high RS)	Dogs (Beagles)	Healthy	11.5 ± 0.38 years	Feed supplemented @ 1.46% RS	61 days	-	↑ proglucagon level ↓ fecal pH ↑ fecal butyrate, propionate, and total SCFA concentrations	[120]

“-”: unreported; HFD: High-fat diet; ↑: increased; ↓: decreased.