Table 2.

Traditional probiotics and next-generation probiotics and their benefits.

Probiotic Genus *	Found in the Body	Dietary Source:	Potential Benefits Attributed to Specific Strains	References
Lactobacillus	Colon, gut and vagina	Yoghurt, fermented foods, bread, sauerkraut, wine etc.	Gastroenteritis, easing lactose intolerance, immune system modulation, alleviating inflammation, lowering cholesterol, cancer protection, modulating brain activity, preventing pathogen colonisation, bile resistant.	[60,61,62,68,82,83,84,85,86,87]
Bifidobacterium	Colon, oral cavity, breast milk and vagina	Yoghurt, kombucha, sauerkraut, kefir etc.	Bile resistant, easing lactose intolerance, antibiotic-associated diarrhoea, eczema, immune system modulation, cholesterol lowering abilities	[68,71,88,89,90]
Saccharomyces	Colon, decaying fruit, plants, soil, insects	Wine, yoghurt, kombucha, sauerkraut etc.	Travellers’ diarrhoea, antibiotic-associated diarrhoea, preventing recurring Clostridium difficile infections, irritable bowel syndrome	[77,78,79]
Escherichia coli	Colon	Capsules	Antagonistic properties against a variety of pathogens, production of defensin, tight-junction protein modification, irritable bowel disorder, constipation, pro-inflammatory properties and colon cancer	[50,51,52,53,54,91]
Bacteroidetes	Colon	-	Immune system modulation, intestinal homeostasis	[92,93,94]
Akkermansia	Colon	-	Gut barrier function, fat mass storage, glucose homeostasis, immune system stimulation, production of Vitamin B12	[95,96,97,98,99,100,101]
Faecalibacterium	Colon	-	Immune system modulation, ease inflammation	[102,103]
Eubacterium	Colon	-	Improve insulin sensitivity, increase energy production, produce Vitamin B12, maintain intestinal homoestasis, colon detoxification, reducing the symptoms of colitis	[104,105,106,107]

* Some of the mentioned genera are regarded as potential probiotics.