Final answer:
The foul-smelling sweat, particularly found in armpits and feet, is a result of bacteria and yeast on skin breaking down sweat, especially secretions from apocrine sweat glands. Sweat, while possessing antimicrobial properties, can promote microbial growth due to the moisture it provides. Antiperspirants help reduce body odor by blocking sweat production.
Step-by-step explanation:
Foul-smelling perspiration, often found in the armpits or on the feet, is a result of the breakdown of sweat by bacteria and yeast that exist on the surface of the skin. These fungi and bacteria break down the organic compounds found in sweat, such as the secretions from apocrine sweat glands, causing body odor. Found predominantly in densely hairy areas like armpits and genital regions, these glands release fatty secretions that local bacteria break down.
Sweat comprises water, salts, and other substances like lysozyme and antimicrobial peptides that inhibit microbial growth. However, the moisture provided by sweat to regions like the underarms and groin can increase the potential for microbial growth significantly. Eccrine sweat glands, another type of sweat gland, release sweat that is primarily water.
To reduce sweat and hence the resulting body odor, most commercial antiperspirants use an aluminum-based compound as their primary active ingredient. Upon entering the sweat gland duct, these compounds form a physical block, preventing sweat from coming out of the pore.
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