chapter 24

What is TRUE about stomach microbiota?

Despite the acidic of the stomach, diverse phylotypes of resident microbes thrive in the stomach.

What happens when mice grown in the absence of microbes are inoculated with healthy cecal material from other mice?

Genes associated with glucose uptake, lipid absorption, and lipid transport are activated and the mice gain body fat without increasing energy intake.

Which of these microorganisms is most likely to be found in the human stomach?

Helicobacter pylori

Which of the following is NOT a major question in the Human Microbiome Project?

How can we reduce the number of microbes on the human body?

Only particles smaller than ________ μm in diameter reach the lungs.

10

Which of the following is the genus represented by the greatest diversity of phylotypes on the skin?

Actinobacteria

________ dominate the infant gut microbiota.

Actinobacteria

Which of the following is TRUE about research on the human microbiome?

Advanced nucleic acid sequencing techniques were needed before a good understanding of its microbial abundance and diversity could be developed.

Children with severe dental caries tend to have elevated levels of all of the following bacteria EXCEPT

Aestuariimicrobium.

Important bacterial populations in the stomach include

All of these answer choices

Which of the following is a benefit of studying the human microbiome?

All of these answer choices are possible benefits.

Common probiotics include

Bifidobacterium species.

Vaginitis commonly results from overgrowth of

Candida and Trichomonas vaginalis.

Based upon microbiome projects, the dominant microbial species on the skin is

Propionibacterium species.

Which of the following is known to be TRUE about dog owners and their dogs?

Skin microbes are more common between dog owners and their own dogs than between dog owners and other dogs.

Which of the following is TRUE about the comparison between the mouse gut and the human gut?

The colon and cecum are relatively larger in mice.

Which of the following is TRUE regarding the interaction between hormones and vaginal microbial diversity?

There is an inverse relationship between estradiol levels and microbial diversity.

What is the role of fecal transplants in medicine?

They can provide a healthy microbiota to help treat Clostridium difficle infections.

Which of the following is NOT true about breast fed infants compared with those fed formula?

They have greater numbers of Clostridium difficile.

Which of the following is TRUE of vaginal bacterial communities?

Those dominated by Lactobacillus crispatus are more resilient than those dominated by Lactobacillus iners.

What is the difference between vaginitis and vaginosis?

Vaginitis is more serious and vaginosis is subclinical.

The damaged areas of teeth caused by organic acids produced by dental plaque are called

dental caries.

Extensive microbial growth in a thick bacterial layer on the teeth is called

dental plaque.

The human oral microbiota consists of

diverse aerobic and anaerobic microorganisms.

The human gastrointestinal tract includes all of the following EXCEPT the

epiglottis

A healthy vaginal microbiome is dominated by Candida. t/f

false

A plant-rich diet increases the risk of inflammatory bowel disease, a leaky gut, and inflammation. t/f

false

A vaginal swab would suggest vaginosis if there were relatively high numbers of gram- positive rods and relatively low numbers of gram variable rods. t/f

false

All microorganisms that live in the human body are harmful. t/f

false

Bacteria found in the mouth in the first years of life are well-adapted to biofilm formation. t/f

false

Biofilms in the human mouth primarily contain pathogens. t/f

false

Consumers can purchase probiotic foods that are 100% proven to be highly effective. t/f

false

Normal microbiota is usually found in the blood, lymph, and nervous systems of the body. t/f

false

Probiotics do not contain living microbes. t/f

false

The presence of Propionibacterium acnes is always associated with inflammatory disease. t/f

false

The upper respiratory tract usually has a considerable amount of resident microflora in a healthy adult. t/f

false

The use of fecal transplants has dramatically improved outcomes for patients with Clostridium difficile infections. t/f

false

Volatile fatty acids are produced primarily from the breakdown of proteins. t/f

false

Infants born via C-section have

fewer Bacteriodes species than those born vaginally.

Clostridium difficile infections most often occur

following antibiotic treatment.

Which of the following is NOT a function of the human gut microbiome?

iron and trace metal absorption

The most heavily colonized human organ by bacteria is the ________, containing 1011-1012 bacterial cells per gram.

large intestine

Individuals who have chronic periodontitis tend to have

lower microbial diversity than those without.

Gut microbiota is known to be linked with

obesity and inflammatory bowel syndrome.

The human microbiome contains all

organisms present in and on the body.

Normal microbiota helps to ________ colonization of pathogenic organisms.

prevent

Following antibiotic therapy, patients are often administered ________ to facilitate recolonizaton of normal microbiota in the intestines.

probiotics

Weight gain and obesity may be partly caused by certain gut microbial communities that

produce more volatile fatty acids by fermentation.

Which of the following are NOT found in the gastrointestinal tract of healthy humans?

protists

A microbial community that does not change when exposed to stressors is called

resistant

One microenvironment of the skin is an area where glands produce an oily substance called

sebum.

Normal microbiota in the duodenum is

similar to the microbiota in the stomach

More frequent cases of severe C. difficile infection since 2003 is attributed to

the emergence of more virulent and toxigenic strains.

The collective term for the functional collection of microbes living on or in the human body, as opposed to a general term for organisms in an environmental habitat, is

the human microbiome.

Ammonia-oxidizing Archaea can be found on the skin. t/f

true

Bacteria make up about one-third the weight of fecal matter. t/f

true

Clostridium difficile commonly develops in hospitalized patients, but is increasingly seen in non-hospitalized patients traditionally considered to be at lower risk. t/f

true

Crohn's disease and ulcerative colitis are examples of inflammatory bowel syndromes. t/f

true

Elderly individuals have greater proportions of Bacteroidetes in their gut microbiota compared with younger individuals. t/f

true

Goblet cells in the intestine produce antimicrobial peptides. t/f

true

Goblet cells in the intestine secrete mucin. t/f

true

Malassezia spp. are the most common fungi present on the skin of humans. t/f

true

Methanogenic Archaea are more common in obese humans compared with thin humans. t./f

true

Protists are NOT normally found in the gastrointestinal tract of healthy individuals. t/f

true

Some yogurts contain probiotics and prebiotics. t/f

true

The gut microbiota is relatively stable over long time periods in healthy adults, suggesting its highly evolved role in the human body. t/f

true

The male reproductive tract is generally sterile except for the distal portion of the urethra. t/f

true

Vaginal acidity in the adult female is due to acid production by Lactobacillus acidophilus. t/f

true

Volatile fatty acids include acetate, proprionate, and butyrate. t/f

true

The Nugent score is used to diagnose

vaginosis

The following compounds are all produced by intestinal microbiota EXCEPT

vitamin C

The vagina of an adult female is

weakly acidic

Which of the following environmental and host factors influence the composition of the resident microbiota on the skin?

age, personal hygiene, and weather

The gut microbiota resembles the adult microbiota

around age 3.

The pouch at the beginning of the large intestine is called the

cecum.

Which study set out to generate genomic sequences from 200 strains of bacteria isolated from the human body?

NIH JumpStart Program

Which of the following is NOT true of human gut microbes?

The population size is low, but the diversity is high.

The host-microbiome supraorganism refers to

a body and all of its associated microbes.