Role of natural products and intestinal flora on type 2 diabetes mellitus treatment

Table 1 Effects of short chain fatty acids on intestinal epithelial cell homeostasis and function

Effects of SCFAs
Energy substrate for ATP production
Receptor activation, mainly G protein coupled receptors
Maintaining barrier function and integrity
Modulation of immunity and control of inflammation, Treg differentiation, modulation of inflammation mediators
Modulation of intracellular permeability
Epigenetic effects by inhibition of histone deacetylases, hyperacetylation of histones and modulation of gene expression

ATP: Adenosine triphosphate; Treg: Regulatory T cell; SCFAs: Short chain fatty acids.

Table 2 Effects of natural products on type 2 diabetes mellitus

Natural products	Sources	Antidiabetic mechanisms
Allicin	Garlic	Maintains glucose homeostasis; Maintains insulin sensitivity
Saponin	Polygonatum kingianum	Lowers blood sugar and lipopolysaccharide; Improves glucose metabolism
Flavanoids	Enteromorphaprolifera	Decreased blood glucose levels; Improve glucose tolerance
Anthocyanin	Strawberry	Improved lipid, glucose metabolism, insulin resistance, gut barrier function; Reduce low grade inflammation and stimulate the host immune system
Alkoloids	Rhizomz coptidis	Improved insulin sensitivity, glucose homeostasis, blood lipids
Catechin	Rhododendron groenlandicum	Reduced intestinal endotoxin levels; Improve mucosal barrier function; Lower serum glucose
Flavanols	Green tea leaves, red wine, cocoa, cranberry	Increase glucose tolerance; Increase insulin secretion