Short-chain fatty acids: possible regulators of insulin secretion

The benefits of gut microbiota-derived short-chain fatty acids (SCFAs) towards health and metabolism have been emerging since the past decade. Extensive studies have been carried out to understand the mechanisms responsible in initiating the functionalities of these SCFAs towards body tissues, which greatly involves the SCFA-specific receptors free fatty acid receptor 2 (FFAR2) and free fatty acid receptor 3 (FFAR3). This review intends to discuss the potential of SCFAs particularly in regulating insulin secretion in pancreatic β-cells, by explaining the production of SCFAs in the gut, the fate of each SCFAs after their production, involvement of FFAR2 and FFAR3 signalling mechanisms and their impacts on insulin secretion. Increased secretion of insulin after SCFAs treatments were reported in many studies, but contradicting evidence also exist in several other studies. Hence, no clear consensus was achieved in determining the true potential of SCFA in regulating insulin secretion. In this review, we explore how such differences were possible and hopefully be able to shed some perspectives in understanding SCFAs-signalling behaviour and preferences.

Biofunctional characteristics of banana peel dietary fibre (BPDF) and its associated in vitro antidiabetic properties

The potential applications of banana peel waste can resolve environmental issues; however, the potentials of banana peels as antidiabetic remain unexplored. Therefore, the present work was carried out to investigate the biofunctional and surface properties of banana peel dietary fibre (BPDF) and its enzyme inhibitory activities. The water holding capacity (WHC), oil holding capacity (OHC), swelling capacity (SC), and glucose absorption capacity (GAC) were measured, and the glucose retardation index (GDRI) was analysed. The inhibitory effect of BPDF against α-amylase activity was also observed. The findings showed that the WHC (0.7 g/g), OHC (0.3 g/g), SC (0.73 mL/g), GDRI (6.58 - 31.72%), and GAC (0.162 - 19.211 mmol/g) of BPDF could have the potential in regulating diabetes, and explain the physiological effects of dietary fibre. The surface morphology of BPDF was analysed using scanning electron microscope. Interestingly, BPDF hampering effects on the diffusion of glucose through α-amylase inhibitory activity with IC50 8.9 µg/mL was found to be comparable to acarbose (IC50 8.6 µg/mL), thus showing potential in lowering postprandial blood glucose (type 2 diabetes mellitus).

Diet-induced metabolic changes of the human gut microbiome: importance of short-chain fatty acids, methylamines and indoles

The human gut is a home for more than 100 trillion bacteria, far more than all other microbial populations resident on the body's surface. The human gut microbiome is considered as a microbial organ symbiotically operating within the host. It is a collection of different cell lineages that are capable of communicating with each other and the host and has an ability to undergo self-replication for its repair and maintenance. As the gut microbiota is involved in many host processes including growth and development, an imbalance in its ecological composition may lead to disease and dysfunction in the human. Gut microbial degradation of nutrients produces bioactive metabolites that bind target receptors, activating signalling cascades, and modulating host metabolism. This review covers current findings on the nutritional and pharmacological roles of selective gut microbial metabolites, short-chain fatty acids, methylamines and indoles, as well as discussing nutritional interventions to modulate the microbiome.

Acrylamide toxicity and its biodegradation

Acrylamide is a synthetic monomer that has been classified as toxic and carcinogenic apart from its diverse application in the industry. Its application is in the formation of polyacrylamide. Polyacrylamide usage is diverse and is found as herbicide formulation, as soil treatment agent and in water treatment plants. Deaths and sickness due to the accidental exposure to acrylamide has been reported while chronic toxicity is also a source of problem. This review highlight on the toxic effect of acrylamide to various organism like human, animal and plant. This review also discusses on the potential use of biological technologies to remediate acrylamide pollution in the environment and the degradation pathways these microorganisms utilize to assimilate acrylamide as a nitrogen, carbon or both as carbon and nitrogen sources.