How Microbes Can Be Helpful or Harmful

Microbes, or microscopic organisms, are everywhere, residing in food and even inside the human body. Microbes are usually associated with being harmful and some can cause illness, but many microorganisms such as probiotics are beneficial to our health.

Functions

• Beneficial microbes are important in life. Microbes perform functions such as nutrient recycling by breaking down dead carcasses, improving human health through digestive assistance and boosting immunity, and provide us with food such as beer and yogurt. Some microbes even help break down waste produced from industry and households, and they are used in the treatment of our wastewater by removing organic materials from the water.

Examples

• Some beneficial microbes include lactobacillus acidophilus which is a probiotic that lives in our digestive tract aiding digestion and suppression of disease-causing bacteria. Saccharomyces cerevisiae, or baker's yeast, makes bread rise. Pseudomonas putida is one of many microbes used at water treatment plants to clean waste from sewage water. Microbes can also be used as natural antibiotics to treat infections such as the microbe, streptomyces.

Warning

• Harmful microbes are a significant cause of disease in animals, humans and crops. They are also associated with spoilage and decomposition of our foods, textiles and dwellings. An organism that can cause infectious disease is called a pathogen. Four groups of microbes that contain pathogens are bacteria, fungi, protozoa and the viruses. Some harmful microbes include smallpox caused by a virus, malaria from a protozoan and cholera which is caused by a bacterial pathogen.