Sunday, August 25, 2019
ABS 394
Subtopic 2C!
•What makes up our microbiota?
The microbiota generally refers to the collection off all organisms,
composed of bacteria, fungi, protozoa, viruses and even very small
animals on or inside the human body. They are the tiny organisms that
live in our intestinal tract (gut).
•What health conditions have been linked to our
microbiome (microbiota)?
obesity, asthma, allergies, rheumatoid arthritis, diabetes
•What factors influence the exact composition of a person’s microbiome
(microbiota)?
depends on what you eat, where you live, who you live with, what you
touch and even how you were born
•How do babies first acquire their microbiota?
The way we are born, whether its natural or cesarian, influences the type
of microbes we first contact. Babies born naturally come in contact with
microbes in the mothers intestinal vaginal pools. A cesarian birth tend to
be colonized with microbes typically found on the skin and hospitals.
Breast fed babies will differ from formula fed babies.
•What physiological functions in humans are known to be influenced by
light and dark?
eating late at night and too much electric light after sunset. Changes
occur in hunger, body temperature, sleep propensity, hormone
production, activity level, metabolic rate and more.
•Which organ’s activity seems to be most influenced by the circadian
rhythm of the microbiota?
liver
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Sunday, August 25, 2019
•Which health conditions are suspected to be influenced by changes in the
rhythm of microbiota?
obesity, metabolic syndrome
•What changes are observed in the microbiome of Hadza between the dry
and wet seasons?
The microbiomes are more diverse during dry seasons than in wet, and
that taxa present during one dry season was consistent with the other dry
season. The phylum Bacteriodetes declined during rainy periods, while
the phylum Firmicutes remained stable. Repeated sampling of eight
individuals’ microbiota across the seasons showed that some other taxa-
such as the Spirochates- dropped below the limits of detection during the
wet season. The authors found that the production of enzymes that
microbes use to digest carbohydrates varied seasonally as well. In the dry
season, when a large proportion of the Hadza diet is made up of hunted
game, there was greater diversity of these enzymes than in the wet
season, when the Hadza more often eat berries and honey.
•How do the microbiomes of industrialized people compare to non-
industrialized people in terms of the level of plant-digesting enzymes they
contain?
Industrialized microbiomes contained less diversity in these enzymes,
and had lower levels of the enzymes primarily used to digest plants. The
microbiomes from non-industrialized groups were more similar to each
other than to the microbiomes from industrialized regions, which
clustered together. The authors found that the groups of microbes that
varied seasonally in the Hadza were largely absent in the industrialized
microbiomes, but present in the microbiomes of people who live
similarly to them.
•What one beneficial compound do the microbiota produce when they feed
on fiber in our intestines?
butyrate
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Sunday, August 25, 2019
•What is the link between the amount of fiber we consume and colon
cancer rate?
the amount of fiber we consume helps microbes produce butyrate that
helps in preventing cancer. The less butyrate we have the higher harmful
compounds we have that can lead to cancer.
•What are the main conclusions obtained from switching diets of Africans
and African Americans?
The amount of harmful compounds increased in the colons of the
africans while the amount of beneficial compounds like butyrate
increased in the African Americans. You can influence your risk in colon
cancer in just two weeks. We’re not just eating for ourselves, we’re
eating for the trillions of microbes that inhabit us like the ones that help
protect breast-fed babies.
•In what way does Westernization affect the diversity of the microbiome?
It reduces the diversity of richness in microbial life in the gut.
•Are microbiomes high or low in diversity beneficial for health?
High
•What is one demonstrated negative health consequence of a diminished
intestinal mucus layer?
bacteria can feed on the protective mucus lining. A recent study shows
that when microbes are starved of fiber, they can start to feed on the
protective mucus lining of the gut, possibly triggering inflammation and
disease.
•What is a possible outcome when the fiber content of the diet alternates
daily between high and low?
A part-time high-fiber diet is not enough to keep guts healthy. Mice had a
mucus layer about half the thickness of mice on the consistently high-
fiber diet.
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Sunday, August 25, 2019
•Currently how much fiber do average Americans get daily? How much
fiber do we estimate that we used to get as hunter-gatherers?
Today's Western diet, however, is exceedingly fiber-poor by historical
standards. It contains roughly 15 grams of fiber daily, Sonnenburg noted.
For most of our early history as hunter-gatherers, we were likely eating
close to 10 times that amount of fiber each day.!
!
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