Question

Bacteria that live in the human intestine assist digestion and feed on nutrients the human consumed. This relationship might best be described as: a. commensalism. b. mutualism. c. endoparasitism. d. ectoparasitism. e. predation

Short answer

The best description of the relationship between the bacteria and the human in this scenario is mutualism (option b).

Step-by-step solution

Understand the Terms

First, let's understand what each term means - commensalism is a relationship where one organism benefits while the other is unaffected; mutualism is where both organisms benefit; endoparasitism and ectoparasitism are relationships where the parasite lives inside or outside the host, respectively, and the host is harmed; finally, predation involves one organism preying on another.

Interpret the Question

The question describes a scenario where bacteria live in the human intestine, helping with digestion and getting nutrients in return. This relationship benefits both the human and the bacteria. Therefore, let's identify which term refers to a mutually beneficial relationship.

Identify the Correct Answer

Considering the definitions from Step 1, the only relationship that describes a mutual benefit to both parties involved is mutualism.

Key concepts

Bacteria in the Human Intestine

Our intestines are home to a diverse community of bacteria. These bacteria play an essential role in maintaining our health. More than just inhabitants, they assist in breaking down complex carbohydrates and proteins that our body finds difficult to digest on its own. This process allows us to absorb nutrients that would otherwise pass through our digestive system unused.
In essence, these bacteria are tiny helpers that provide a big benefit. They break down fibers, contribute to the production of vitamins like B12 and K, and compete with harmful pathogens to prevent infections. Without them, our digestive system would be less efficient, and we might suffer from deficiencies in essential nutrients.

Commensalism

In nature, organisms often form relationships that help them survive. One such relationship is known as commensalism. In a commensal relationship, one organism benefits while the other is neither helped nor harmed.
A classic example is the relationship between barnacles and whales. The barnacles get transportation and access to nutrient-rich waters by attaching themselves to whales, while the whales remain unaffected. However, this is not the case with the bacteria in our intestines, as both parties benefit.

Digestive System Assistance

The bacteria in our intestines provide critical assistance to our digestive system. They help break down and ferment foods, especially dietary fibers that would otherwise remain undigested. This process not only makes nutrients more accessible but also produces beneficial by-products like short-chain fatty acids.
Additionally, these bacteria play a crucial role in maintaining the health of our gut lining and supporting our immune system. By assisting the digestive process, they help prevent gut-related illnesses and boost our overall health.

Human Microbiome

The human microbiome is the community of microorganisms that reside in our bodies, predominantly in the gut. It's a complex ecosystem that includes bacteria, fungi, and archaea. These microorganisms outnumber the cells in our body and carry over 100 times more genetic material than the human genome.
An essential aspect of the human microbiome is its impact on our health. It helps regulate digestion, synthesizes vitamins, and enhances our immune functions. A balanced microbiome is crucial for maintaining good health, protecting us from pathogens, and even influencing our mood and mental health. Keeping our microbiome healthy is key, and it thrives on a varied diet, regular exercise, and reduced antibiotics use.