Final answer:
Probiotics are live microorganisms that promote a healthy balance of gut flora by controlling the growth of harmful bacteria and aiding in digestion and vitamin production.
Step-by-step explanation:
The live microorganisms that help control the growth of pathogenic bacteria in the large intestine are known as probiotics. These helpful bacteria are crucial for maintaining a healthy gut flora, and they perform a variety of functions such as producing vitamins like vitamin B12 and vitamin K, controlling the growth of harmful bacteria, and aiding in the digestion of plant material by producing enzymes. Probiotics can be found in fermented foods like yogurt and are also available as dietary supplements. These microorganisms differ from prebiotics, which are non-digestible food ingredients that selectively stimulate the growth or activity of beneficial bacteria, and antibiotics, which kill or inhibit the growth of bacteria. Importantly, for probiotics to provide their beneficial effects, they must arrive alive in the gastrointestinal tract where they can adhere to the intestinal epithelium and maintain their metabolic activity.