Question

What types of microbes live in the intestines? a. Diverse species of bacteria, archaea, and fungi, especially Bacteroides and Firmicutes bacteria b. A narrow range of bacteria, especially Firmicutes c. A narrow range of bacteria and fungi, especially Bacteroides d. Archaea and fungi only

Short answer

a. Diverse species of bacteria, archaea, and fungi, especially Bacteroides and Firmicutes bacteria.

Step-by-step solution

Understanding the Microbiota of the Intestines

The human intestines host a complex and diverse community of microorganisms which include bacteria, archaea, fungi, and viruses. This complex community is referred to as the microbiota or microflora of the intestines.

Identifying Key Players in the Intestinal Microbiota

Among the bacteria, two dominant phyla are Bacteroidetes and Firmicutes, although many other types of bacteria are also present. In addition to bacteria, the gut microbiota also includes archaea, a separate domain of life, and fungi.

Selecting the Correct Option

Option (a) lists a diverse range of microbes including bacteria, archaea, and fungi, and mentions Bacteroides and Firmicutes, which does match the composition of typical human gut microbiota. Therefore, this is the correct answer.

Key concepts

Gut Microflora Diversity

The human gut is a bustling metropolis of microbes, each playing a unique role in health and disease. This diverse community, known as the gut microflora, includes a wide array of bacteria, archaea, fungi, and viruses. Scientists estimate that each person harbors tens of trillions of microbes, comprising hundreds to thousands of different species.

Why is this diversity important? Just like a diverse ecosystem is more resilient to changes, a diverse gut microflora can help withstand and recover from disruptions like illnesses, antibiotic use, or dietary changes. Furthermore, each microorganism contributes differently to digestion, immune function, and even mood regulation. Understanding this complexity is crucial for developing strategies to promote health and treat diseases.

Bacteroidetes and Firmicutes

In the vast framework of the gut microbiota, two phyla stand out for their abundance: Bacteroidetes and Firmicutes. These groups don’t just lead in numbers; they also play pivotal roles in our gut.

Role of Bacteroidetes

Bacteroidetes bacteria are known for breaking down complex molecules like carbohydrates and fiber. This function is critical for gut health, as it helps produce energy and nutrients for our body and other gut inhabitants.

Role of Firmicutes

Firmicutes, on the other hand, are adept at extracting energy from the diet and have been linked to fatty acid synthesis. This group is diverse, containing both beneficial microbes and potential pathogens. Interestingly, the balance between Bacteroidetes and Firmicutes can affect our body's energy balance and has been studied in relation to obesity.

The intricate balance between these two phyla and how dietary choices influence their populations is an ongoing area of research. Their prevalence and functions underscore their importance in human health.

Human Gut Microbiome Ecology

The ecology of the human gut microbiome is a dynamic and intricate system where microbes interact with each other and with their human host. It's governed by a variety of factors including diet, genetics, age, and environment.

Communication between microbes and the human body happens through a multitude of signals and substances, influencing not only the microbiome's composition but also the health of the host. Disturbances in this ecology, such as a loss of microbial diversity or the overgrowth of harmful microbes, can lead to conditions like inflammatory bowel disease, allergies, and even obesity.

Researchers aim to chart the complexity of gut microbiome ecology to identify patterns that could lead to better diagnostic tools, personalized diets, and precision probiotics that could help maintain or restore a healthy gut ecosystem. Ultimately, understanding this ecology not only helps us appreciate the sophistication of our inner microbial world but also opens doors to innovative therapies for many diseases.