Natural compounds kill bacteria much in the same way that industrially prepared chemicals or treatments do. Natural compounds that kill bacteria are called bacteriocins, or in other words the extracellular enzymes produced by bacteria to kill other bacteria.

Many bacteriocins kill bacteria by cleaving essential components in cell walls such as beta-lactam. (This is also the same way that penicillin works, which is produced by fungi.) Bacteriocins can also cause cellular lysis by activating the cells apoptotic cycle. (programmed cell death)

One of the more common ways that natural compounds kill bacteria is by preventing them from producing proteins that are required for the cell to survive. Also, these compounds prevent the uptake and formation of folates which is required for bacterial metabolic processes which also causes cell death.

Yes, in a narrow sense bacteriocins are antibiotic, since they are substances produced by a bacteria to prevent the growth or invasion of other similar bacteria in their territory. However, they are not considered to have broad-spectrum antibiotic properties since they are somewhat specific.

any substances that hampers survival of a living organism is anti-bio. it is only due to some accidents in history that we discovered some metabolic by products of certain microorganisms caused the death or inhibition of others, hence the term antibiotics..... you can check my articles in internal medicine in this site lowellmd202.blogspot.com

The normal flora occupy available colonization sites which makes it more difficult for other microorganisms (nonindigenous species) to become established. Also, the oral flora contribute to host nutrition through the synthesis of vitamins, and they contribute to immunity by inducing low levels of circulating and secretory antibodies that may cross react with pathogens. Finally, the oral bacteria exert microbial antagonism against nonindigenous species by production of inhibitory substances such as fatty acids, peroxides and bacteriocins.