A systematic review and meta‐analysis of in vitro antibacterial activity of depolymerised polysaccharides

Abstract

SummaryThe relationship between molecular weight (MW) and antibacterial activity of depolymerised polysaccharides has often been inconsistent. Therefore, a meta‐analysis was performed to elucidate the effectiveness of depolymerisation methods in improving the antibacterial capabilities of polysaccharides. Chitosan was the most studied polysaccharide (65.55% of the included studies) with antibacterial activities, followed by sulfated algal polysaccharides, alginate, β‐glucan, pectin, xanthan, gum, xylan, agar, maltodextrin and miscellaneous polysaccharides extracted from various natural sources. The meta‐analysis revealed that regardless of polysaccharide type, depolymerised polysaccharides exerted superior inhibitory activity against Escherichia coli than against Staphylococcus aureus. Furthermore, low MW (<10 kDa) anionic and non‐ionic polysaccharides were more effective than chitosan (10–100 kDa) in this regard. Though the high heterogeneity of the current meta‐analysis (I2 > 80%) limits the interpretation of results, it also implies that an understanding of polysaccharide bioactivity is currently lacking. More studies are needed to reach a reliable conclusion about the possible antibacterial activity of low‐MW polysaccharides.