Woodfordia fruticosa extract supplementation stimulates the growth of Lacticaseibacillus casei and Lacticaseibacillus rhamnosus with adapted intracellular and extracellular metabolite pool.

AIM: To investigate the effect of Woodfordia fruticosa extract (WfE) on two probiotic bacteria: Lacticaseibacillus casei and Lacticaseibacillus rhamnosus. METHODS AND RESULTS: WfE supplementation at 0·5 and 1 mg ml-1 stimulated probiotic growth (P < 0·05), enhanced adhesion to CaCO2 cells (P < 0·05) while inhibiting foodborne pathogens Escherichia coli and Staphylococcus aureus (P < 0·05). 1 H-NMR based metabolomic studies indicated higher glucose : lactate and glucose : acetate in the extracellular matrix with significant variation (P < 0·05) in intracellular concentrations of lactate, acetate, glutamate, dimethylamine, phenylalanine, branched-chain amino acids and total cellular lipid composition. Fatty acid methyl ester analysis showed a chemical shift from saturated to unsaturated lipids with WfE supplementation. PCA plots indicated clear discrimination between test groups, highlighting variation in metabolite pool in response to WfE supplementation. CONCLUSION: Phytonutrient-rich WfE exhibited prebiotic-like attributes, and probiotic bacteria showed altered metabolite pools as an adaptive mechanism. SIGNIFICANCE AND IMPACT OF THE STUDY: This is the first report providing insights into the prebiotic-like activity of WfE on gut representative probiotics. The extended metabolomic studies shed light on the positive interaction between phytonutrients and beneficial bacteria that possibly help them to adapt to a phytonutrient-rich WfE environment. WfE with potential prebiotic attributes can be used in the development of novel synbiotic functional products targeting gut microbial modulation to improve health.

Plectranthus amboinicus leaves stimulate growth of probiotic L. plantarum: evidence for ethnobotanical use in diarrhea.

ETHNOPHARMACOLOGICAL RELEVANCE: Leaves of Plectranthus amboinicus are consumed in India along with buttermilk (a probiotic source) during pathogen induced diarrhea. This treatment is known to reduce the number of episodes as well as duration of diarrhea. AIM OF THE STUDY: In the background of its ethnobotanical use, the present investigation was carried out to determine whether, apart from having an antimicrobial activity on pathogens, the leaves could possibly also have a positive effect on the beneficial microflora of the gut resulting in accelerated microbial ecological balance. MATERIALS AND METHODS: The growth stimulating activity of the hot water extract (HWE) of P. amboinicus leaves on probiotic Lactobacillus plantarum was determined by microbroth dilution technique and viable plate count method in selective medium (MRS) as well as in fermented milk. The ability of the bacteria to utilize the phytoconstituents of HWE primarily phenolic acids and sugars was determined by assaying for phenolic acid decarboxylase by SDS-PAGE and ß-galactosidase activity by ß-gal ONPG assay. RESULTS: HWE of P. amboinicus leaves inhibited growth of pathogens (Escherichia coli and Salmonella typhimurium) while stimulated the growth of L. plantarum. SDS-PAGE gel showed the presence of phenolic acid decarboxylase enzyme induced in the presence of HWE in L. plantarum indicating the utilization of polyphenols by the bacteria. Cells grown on HWE also showed ß-galactosidase activity indicating their ability to utilize sugars present in HWE. CONCLUSION: Indian borage leaves have a prebiotic effect on the probiotic bacteria (L. plantarum) which utilizes the phytoconstituents of the leaves by producing necessary metabolic enzymes. This work provides evidence in the traditional use of the leaves in the alleviation of diarrhea by accelerating microbial gut balance during infection.