This document analyzes the relationship between food and the intestinal microbiota in humans. It discusses what intestinal microbiomes are, their roles, and their relationship with the host. The document explores how diet can modulate gut microbiome composition and influence enterotypes. It summarizes research studies that link long-term diet to enterotypes and show the gut microbiome of malnourished children remains immature. The conclusion is that food affects the gut flora, which in turn impacts health and development.

1. Analyzing the relationship
between food and
intestinal microbiota in
humans
Irene Polo
FIU Agroecology Program
17 July 2014
ipolo1969@gmail.com

2. Organization
 What are Intestinal Microbiomes?
 Roles of Intestinal Microbiota
 Relationship with Host
 Link to Diet
 Enterotypes
 Research Studies
 Conclusion

4. Location:
 Human gastrointestinal tract (GIT): diverse
 Gut most populated area (Shetty, 2013)
Colonization:
 Begins before birth- ex. Firmicutes,
Bacteroidetes, etc. (Aagaard, 2014)
 Composition dependent on factors: age, diet,
genetic composition, gender, geographic
location, and health status
 Provide microbial measure of human atal
development
 Toddlers should have adult-like intestinal
microbiome(Subramanian, 2014)
Introduction to Intestinal Microbiome
Lactobacillus bulgaricus Bacteria
are Gram-positive prokaryotes
common in the body and used in
the production of yogurt. SEM
X2400

5.  Strengthen Immunity
 Humoral
 Protection against pathogens (Shetty, 2013)
 Many produce bacteriocines- anti-bacterial
properties (Karpinski, 2013) (Shehata, 2013)
 Nutrient processing
 Stimulation of angiogenesis
 Regulation of host fat storage
 Energy source for colonic epithelial cells
 Produce vitamins, that cannot be
synthesized by the host
 Influences the host physiology (Shetty, 2013)
Roles of Intestinal Microbiota
SEM of Lactobacillus bulgaricus in yogurt.
Microscope mag. 7000x, image width W:
13.6

6. Intestinal Microbiomes: Relationship
with Host
 Relationship = Health of Host
(Shetty, 2013)
 Mutualistic
 Sometimes pathological: obesity,
diabetes, atherosclerosis, and
inflammatory bowel diseases (Wu,
2011), coronary heart disease
 Metabolic diseases are associated
with changes in the gut
microbiome(Shetty, 2013)
SEM image showing Salmonella
typhimurium invading cultured human cells

7. Intestinal Microbiomes: Link
to Diet
 Co-evolution driven by host diet
(Shetty, 2013)
 Diet modulates gut microbiome
composition (Wu, 2011)

8. Enterotypes
 Enterotypes- dominant microbiota in
gut
 Type 1: Bacteroides
 Animal Meat and fats
 Type 2: Prevotella
 Carbohydrates
 Type 3: Ruminococcus
 Cellulose
 Enterotype clustering appears independent of
nationality, sex, age, or body mass index (BMI).
(Wu, 2011)
 (Arumugam, 2011)(Wu, 2011)
Bacteroides biacutis—one of many
commensal anaerobic Bacteroides
spp. in the GIT cultured in blood
agar medium for 48 hours

9. Linking Long-Term Dietary Patterns with
Gut Microbial Enterotypes
Aim:
 Characterize dietary and environmental
variables affecting the microbiota
Methods 1:
 98 subjects
 Diet inventories
 16S rDNA sequencing - characterize fecal
samples
 Clustered into enterotypes: Bacteroides and
Prevotella. (Wu, 2011)
Results:
 Long-term diet correlated with enterotype

10. Linking Long-Term Dietary Patterns
with Gut Microbial Enterotypes
Methods 2:
 10 subjects (all Bacteroides)
 Short-term controlled-feeding experiment
(CAFE)
 Test the stability of the gut microbiome
 High-fat/low-fiber or low-fat/high-fiber diets
 Sampled over 10 days
Results:
 None switched stably to the Prevotella
(carbohydrate) enterotype
 Microbiome composition changed detectably
within 24 hours of both diets (Wu, 2011)

11. Linking Long-Term Dietary Patterns with
Gut Microbial Enterotypes
Conclusion:
 Only the long-term diet was
correlated with enterotype
Further Research:
 Do Bacteroides enterotype have
a higher incidence of diseases
associated with a Western diet?
 Could long-term dietary
interventions stably switch
individuals to the Prevotella
enterotype?

12. Persistent gut microbiota immaturity in
malnourished Bangladeshi children
Aim:
 Determine whether healthy
postnatal development is perturbed
in malnutrition
Methods 1:
 50 Healthy Bangladeshi children
 Monitored during 2 years after birth
 996 fecal samples collected
monthly
 Identified bacterial taxa at different
chronologic ages (Subramanian,
2013)

13. Persistent gut microbiota immaturity in
malnourished Bangladeshi children
Methods 2:
 6 to 20-month-old children
 SAM- severe acute malnutrition
 MAM- moderate acute malnutrition
 Fecal samples before, during, and after
2 Nutritional Interventions
Results:
 SAM: significant microbiota immaturity
 Immaturity partially ameliorated
following nutritional interventions
 Immaturity also evident in less severe
forms of malnutrition (Subramanian,
2013)

14. Persistent gut microbiota immaturity in
malnourished Bangladeshi children
Conclusion:
 Malnutrition is a factor in hindered
development
 Gut Flora play a role in
development (Subramanian, 2013)
Further Research:
 Could prolonged nutritional
intervention help to achieve mature
intestinal microbiome?
 Do unhealthy foods in Western
diets affect the gut flora of children
in a way that affects their
development?

15. Not-so-Honorable Mention:
Monsanto
Aim:
 Determine the real impact of
glyphosate on pathogenic and
beneficial poultry microbiota
Results:
 Highly pathogenic bacteria are highly
resistant
 Salmonella Entritidis
 Salmonella Gallinarum
 Salmonella Typhimurium
 Most of the beneficial bacteria were
found to be highly susceptible
 Enterococcus faecalis
 Lactobacillus spp. (Shehata, 2013)

16. Conclusion
 Food affects gut flora
 Gut Flora affects your
health/development
What can we do about it?
 Further Research
 Avoid antibiotics

17. Works Cited
 Aagaard, K., Ma, J., Antony, K. M., Ganu, R., Petrosino, J., & Versalovic, J. (2014). The placenta
harbors a unique microbiome. Science Translational Medicine, 6(237)
 Arumugam, M., Raes, J., Pelletier, E., Le Paslier, D., Yamada, T., Mende, D. R., . . . Bork, P. (2011).
Enterotypes of the human gut microbiome. Nature, 473(7346), 174-80.
 Karpiński, T.,M., & Szkaradkiewicz, A. K. (2013). Characteristic of bacteriocines and their application.
Polish Journal of Microbiology / Polskie Towarzystwo Mikrobiologów = the Polish Society of
Microbiologists, 62(3), 223-235.
 Shehata, A. A., Schrödl, W., Aldin, A. A., Hafez, H. M., & Krüger, M. (2013). The effect of glyphosate on
potential pathogens and beneficial members of poultry microbiota in vitro. Current Microbiology, 66(4),
350-8.
 Shetty, S. A., Marathe, N. P., & Shouche, Y. S. (2013). Opportunities and challenges for gut microbiome
studies in the indian population. Microbiome, 1(1), 24.
 Subramanian, S., Huq, S., Yatsunenko, T., Haque, R., Mahfuz, M., Alam, M. A., . . . Gordon, J. I.
(2014). Persistent gut microbiota immaturity in malnourished bangladeshi children. Nature, 510(7505),
417-21.
 Wu, G. D., Chen, J., Hoffmann, C., Bittinger, K., Chen, Y., Keilbaugh, S. A., . . . Lewis, J. D. (2011).
Linking long-term dietary patterns with gut microbial enterotypes. Science (Washington), 334(6052),
105-108.