Probiotics are live, non-pathogenic microorganisms that confer health benefits by modulating the gut microbiota. The human gastrointestinal tract harbors a complex microbial ecosystem, and the balance of this microbiota is crucial for digestive and systemic health. Among the most extensively studied and utilized probiotics are species formerly classified within the genera Lactobacillus and Bifidobacterium. These organisms not only naturally colonize the human gut but are also consumed through...

Lactic acid bacteria (LAB) and molds are instrumental in fermenting plant-based foods to enhance preservation and ensure year-round availability. These microbial processes convert plant carbohydrates into organic acids and other metabolites that inhibit spoilage organisms and contribute to the sensory qualities of the final product.In sauerkraut production, cabbage goes through a microbial succession that starts with cocci such as Leuconostoc mesenteroides. These microbes begin fermentation by...

The human microbiota begins developing at birth and undergoes continual change as we age. Infancy marks a critical period of microbial sensitivity, offering a “window of opportunity” during which beneficial microbes help mature the immune system. By age three, children typically develop a more stable and diverse microbial community. Newborns acquire microbes from their immediate environment; vaginal delivery favors maternal vaginal microbes, while cesarean births favor microbes from...

Microbial fermentation is central to food biotechnology, enhancing flavor, texture, preservation, and stability. Fermentative microorganisms metabolize carbohydrates into organic acids, alcohols, and other metabolites that inhibit spoilage organisms and improve digestibility while contributing distinctive sensory qualities.In baking, amylases naturally present in flour hydrolyze starch into monosaccharides such as glucose, which Saccharomyces cerevisiae ferments anaerobically. Through...

Microorganisms colonize various regions of the human body, including the mouth, nasal passages, throat, stomach, intestines, urogenital tract, and skin. The total number of microbial cells is estimated to range from 10¹³ to 10¹⁴—comparable to, or exceeding, the number of human somatic cells. This host–microbiome relationship has led to the conceptualization of humans as supraorganisms, wherein microbial communities perform vital roles in development, immunity,...

Microorganisms play a fundamental role in vaccine development, gene therapy, and therapeutic production. Their biological properties are harnessed to advance medicine and public health. Beyond immunization, microorganisms contribute to gut health, antibiotic synthesis, and genetic disease treatment.Live Attenuated and Inactivated VaccinesLive attenuated vaccines, such as the measles, mumps, and rubella (MMR) vaccine, utilize weakened forms of pathogens to closely resemble natural infections.