Table 2. Effects of forest product derived polysaccharides on diabetes via the intestinal microbiota

Name	Compounds	Gut bacteria changed	Mechanisms	References
Plants
Ophiopogon japonicus	Polysaccharides (fructose, glucose)	Actinobacteria↑, Bifidobacterium↑, Desulfovibrionaceae↓, Dorea↓, Ruminococcaceae↓	Insulin resistance↑, glucose tolerance↑, SCFAs↑	(Wang et al., 2019)
Salvia miltiorrhiza	Polysaccharides	Cyanobacteria↓, Firmicutes/Bacteroidetes↓, Bacteroides↑, Lactobacillus↑, Parabacteroides↑, Oscillospira↓, Alistipes↓	Liver total cholesterol↓, triglyceride↓, free fatty acid↓, alanine transaminase↓, aspartate transaminase↓, LDL-C↓	(Wang et al., 2020b)
Rosa roxburghii	Polysaccharides (arabinose, galactose, glucose, mannose, xylose, fructose)	Bacteroidaceae↑, Peptostreptococcaceae↑, Prevotellaceae↑, Rikenellaceae↑, Bacteroidales↑, Lactobacillus↑, Enterocaccaceae↓, Desulfovibrionaceae↓, Clostridiaceae↓, Ruminococcaceae↓, Erysipelotrichoceae↓, Helicobacteraceae↓, Ruminococcaceae↓, Lachnospiraceae↓, Clostridiales↓, Desulfovibrionales↓	PPAR-γ↓, SREBP-1↓, ACC-1↓, fatty acid synthase↓, glucose-6-phosphatase↓	(Wang et al., 2020a)
Apocynum venetum leaves	Polysaccharide-rich extracts	Odoribacter↑, Anaeroplasma↑, Parasutterella↑, Muribaculum↑, Enterococcus↓, Klebsiella↓, Aerococcus↓	Fasting blood glucose↓, serum insulin↓, glycated serum protein↓, serum lipid profiles↓	(Yuan et al., 2020)
Momordica charantia L.	Fermented polysaccharides (rhamnose, arabinose, galactose, glucose, xylose, mannose, galacturonic acid)	Lactococcus laudensis↑, Prevotella loescheii↑, Prevotella oralis↑	Hyperglycemia↓, hyperinsulinemia↓, hyperlipidemia↓, oxidative stress↓, SCFAs↑, pH↓	(Gao et al., 2018)
Cyclocarya paliurus (Batal.)	Polysaccharides (xylose, arabinose, glucose, galactose, rhamnose, mannose)	Ruminococcaceae↑	SCFAs↑, Bax↓, Bcl-2↑, normalized hormone secretion, inflammation↓	(Li et al., 2021)
Plantago asiatica L.	Polysaccharides	Bacteroides vulgatus↑, Lactobacillus fermentum↑, P. loescheii↑, Bacteroides vulgates↑	Blood glucose↓, insulin, total cholesterol↓, triglyceride↓, non-esterified fatty acid↓, maleic dialdehyde↓, HDL cholesterol↑, antioxidant enzyme activity↑	(Nie et al., 2019)
Mushrooms
Grifola frondosa	Polysaccharides (mannose, rhamnose, glucuronic acid, galacturonic acid, glucose, galactose, fucose)	Streptococcus↓, Enterococcus↓, Staphylococcus↓, Aerococcus↓, Alistipes↑	Fasting blood glucose↓, oral glucose tolerance↓, cholesterol↓, triglyceride↓, LDL-C↓	(Guo et al., 2020)
	Polysaccharides (arabinose, mannose, glucose)	Porphyromonas gingivalis↑, Akkermansia muciniphila↑, Lactobacillus acidophilus↑, Tannerella forsythia↑, Bacteroides acidifaciens↑, Roseburia intestinalis↑	IRS 1↑, phosphatidylinositol-3-kinase↑, glucose transporter 4↑, JNK 1↓	(Chen et al., 2019)
Mushrooms
Morchella esculenta	Polysaccharides (mannose, ribose, rhamnose, glucuronic acid, galacturonic acid, glucose, galactose, arabinose, fucose)	Lactobacillus↑, Firmicutes↑, Actinobacteria↓, Corynebacterium↓, Facklamia↓	Endotoxemia↓, insulin resistance-related proinflammatory cytokines IL-1β↓, TNF-α↓, IL-6↓	(Rehman et al., 2022)
Phellinus linteus	Polysaccharides (glucose, mannose, galactose, xylose, arabinose, rhamnose)	Porphyromona↑	Fasting blood glucose↓, glucose tolerance↑	(Feng et al., 2018)
	Polysaccharide extracts (glucose, arabinose, fucose, galactose, xylose)	Roseburia↑, Prevotella↑, Ruminiclostridium-9↑, Lachnospiraceae↑, Blautia↑, Oscibacter↑, Clostridium↓, Escherichia↓, Bacteroidales↓	SCFAs↑, lipopolysaccharides↓	(Liu et al., 2020)
Ganoderma lucidum	Polysaccharides (mannose, glucose, galactose, rhamnose, arabinose)	Aerococcus↓, Ruminococcus↓, Corynebactrium↓, Proteus↓, Blautia↑, Dehalobacterium↑, Parabacteroides↑, Bacteroides↑	Fasting blood glucose↓, insulin↓, butyric acid↑, valeric acid↑, amino acid metabolism↑, carbohydrate metabolism↑, bacterial toxin↓	(Chen et al., 2020)

Please note that most of the results in the presented references are from studies performed on animal models, and additional experiments are required to determine if the results can apply to healthy individuals or humans.
↑: Increased, enhanced, promoted, or positively changed in terms of activity, expression, or concentration.
↓: Decreased, inhibited, repressed, reduced, or negatively changed in terms of activity, expression, or concentration.
SCFAs: short-chain fatty acids, LDL-C: low-density lipoprotein cholesterol, PPAR: peroxisome proliferator-activated receptor, SREBP: sterol regulatory element-binding protein, ACC: acetyl-CoA carboxylase, HDL: high-density lipoprotein, IRS: insulin receptor substrate, JNK: c-Jun N-terminal kinase, IL: interleukin, TNF: tumor necrosis factor.