Disease and microbiota in the gut

Microbiome: all the bacteria, good and bad, that live within and on the surface of the body.

There are some studies that suggest an imbalanced microbiome, either on the skin or in the gut, is the cause of some disease, including autoimmune diseases like diabetes, rheumatoid arthritis, muscular dystrophy, multiple sclerosis, fibromyalgia. There are also studies that show correlation of an incorrect microbiome to obesity.

This study by Ridaura (2013) shows that mice without certain Bacterioides bacteria tend to be obese. It also has some interesting graphs.This study shows that people who are obese tend to have a higher ratio of Firmicutes:Bacteroidetes bacteria. That is, higher Firmicutes and less Bacteroidetes.

This study tries to find a correlation between diabetes type 1 and gut bacteria.

Scientists even divide people into 3 groups based on their gut bacteria composition.

Systemic antibiotics can have a negative impact on these gut bacteria. Some people recover their healthy ratio of bacteria, others never do. And it is suspected that imbalanced bacteria cause other autoimmune problems. So avoid antiobiotics, especially systemic ones.

For more fun sites try these:

• What germs are on your cellphones and shoes? Link. 

Sources

1. Arumugam M, Raes J, Pelletier E, Le Paslier D, Yamada T, Mende DR, Fernandes GR, Tap J, Bruls T, Batto JM, Bertalan M, Borruel N, Casellas F, Fernandez L, Gautier L, Hansen T, Hattori M, Hayashi T, Kleerebezem M, Kurokawa K, Leclerc M, Levenez F, Manichanh C, Nielsen HB, Nielsen T, Pons N, Poulain J, Qin J, Sicheritz-Ponten T, Tims S, Torrents D, Ugarte E, Zoetendal EG, Wang J, Guarner F, Pedersen O, de Vos WM, Brunak S, Doré J; MetaHIT Consortium, Antolín M, Artiguenave F, Blottiere HM, Almeida M, Brechot C, Cara C, Chervaux C, Cultrone A, Delorme C, Denariaz G, Dervyn R, Foerstner KU, Friss C, van de Guchte M, Guedon E, Haimet F, Huber W, van Hylckama-Vlieg J, Jamet A, Juste C, Kaci G, Knol J, Lakhdari O, Layec S, Le Roux K, Maguin E, Mérieux A, Melo Minardi R, M'rini C, Muller J, Oozeer R, Parkhill J, Renault P, Rescigno M, Sanchez N, Sunagawa S, Torrejon A, Turner K, Vandemeulebrouck G, Varela E, Winogradsky Y, Zeller G, Weissenbach J, Ehrlich SD, Bork P. Enterotypes of the human gut microbiome. Nature. 2011 May 12;473(7346):174-80. doi: 10.1038/nature09944. Epub 2011 Apr 20. Erratum in: Nature. 2011 Jun 30;474(7353):666. Nature. 2014 Feb 27;506(7489):516. PubMed PMID: 21508958; PubMed Central PMCID: PMC3728647. NIH abstract. NIH full study.
2. Human Microbiome Project. Studying microbiomes to understand their role in human health. They also have the genomes of reference strains of bacteria. Link here.
3. Giongo, A., Gano, K. A., Crabb, D. B., Mukherjee, N., Novelo, L. L., Casella, G., … Triplett, E. W. (2011). Toward defining the autoimmune microbiome for type 1 diabetes. The ISME Journal, 5(1), 82–91. http://doi.org/10.1038/ismej.2010.92.  
4. Grice EA, Kong HH, Conlan S, Deming CB, Davis J, Young AC, NISC Comparative Sequencing Program, Bouffard GG, Blakesley RW, Murray PR, Green ED, Turner ML, Segre JA; Kong; Conlan; Deming; Davis; Young; Bouffard; Blakesley; Murray; Green; Turner; Segre (2009). "Topographical and Temporal Diversity of the Human Skin Microbiome". Science 324 (5931): 1190–2. Bibcode:2009Sci...324.1190G. doi:10.1126/science.1171700. PMC 2805064. PMID 19478181. NIH full study.
5. Home Microbiome site. Link. "The Home Microbiome Study is lead by PI Jack Gilbert, postdoc Daniel Smith, and technician Jarrad Hampton-Marcell at Argonne National Laboratories, and funded by the Alfred P. Sloan Foundation. This study is working in collaboration with MicroBE.net and the Earth Microbiome Project to bring together microbial samples from as many environments as possible in order to understand how microbial community structure is shaped by environmental factors."
6. Ridaura VK, Faith JJ, Rey FE, Cheng J, Duncan AE, Kau AL, Griffin NW, Lombard V, Henrissat B, Bain JR, Muehlbauer MJ, Ilkayeva O, Semenkovich CF, Funai K, Hayashi DK, Lyle BJ, Martini MC, Ursell LK, Clemente JC, Van Treuren W, Walters WA, Knight R, Newgard CB, Heath AC, Gordon JI. Gut microbiota from twins discordant for obesity modulate metabolism in mice. Science. 2013 Sep 6;341(6150):1241214. doi: 10.1126/science.1241214. PubMed PMID: 24009397; PubMed Central PMCID: PMC3829625. NIH abstract. This one has fascinating charts.
7. Turnbaugh, P. J., Hamady, M., Yatsunenko, T., Cantarel, B. L., Duncan, A., Ley, R. E., … Gordon, J. I. (2009). A core gut microbiome in obese and lean twins. Nature, 457(7228), 480–484. http://doi.org/10.1038/nature07540. Full study at NIH. 
8. Wikipedia page for "microbiota". Many studies here.
9. Turnbaugh PJ, Ley RE, Mahowald MA, Magrini V, Mardis ER, Gordon JI. An obesity-associated gut microbiome with increased capacity for energy harvest. Nature. 2006 Dec 21;444(7122):1027-31. PubMed PMID: 17183312 NIH abstract. "Comparisons of the distal gut microbiota of genetically obese mice and their lean littermates, as well as those of obese and lean human volunteers have revealed that obesity is associated with changes in the relative abundance of the two dominant bacterial divisions, the Bacteroidetes and the Firmicutes."
10. Wolf, K. J., & Lorenz, R. G. (2012). Gut Microbiota and Obesity. Current Obesity Reports, 1(1), 1–8. http://doi.org/10.1007/s13679-011-0001-8. Link to NIH full study. 
11. Zimmer, Carl. Gut Bacteria Divide People into 3 Groups. New York Times, Apr 20, 2011. Link to article.  Link to Nature article.

Master study list: BPA effects by bodily system

NOTE: This list is being moved to a static page here. All updates will appear on the web page, not in this post.  This post will no longer be updated.



BPA is a well-known endocrine disruptor. In some cases it acts like a hormone (ex: estrogen) in some cases it blocks hormones. The dangers of BPA include how common it is, multiple effects in the body, and long-lasting effects. Effects continue even after exposure stops. Most studies listed here control for various variables likes sex and age. Here is a list of studies by system, showing the effects of BPA.

It is my intention to update this as I get more information, and use this as a central source of studies by system. If you have a study to add, please cite it in the comments and don't forget to add a plain text link. I will format the study and add it to this page.

Fun with health maps!

You didn't know obesity could be this fun, could you? Well, obesity is no laughing matter, but maps can be interesting. Some of these might require Javascript or Flash so make sure they are turned on in your browser first.

CountyHealthRankings.org: map many health issues by US county like obesity rate, adult smoking, inactivity, teen births, uninsured, high school graduation, unemployment, children in poverty, income inequality, violent crime, physical environment, air pollution, drinking water violations, severe housing problems, and more.

A US health map with time slider. Map many factors, one at a time, and see how they changed over time. Some of the items you can map: alcohol use (any at all, binge drinking, and more), hypertension (various factors), life expectancy, obesity, physical activity (various types), poverty, smoking (daily and total).

78% of Americans are overweight or obese. (WHO 2010). A world map showing how common obesity is by country. Look at which nations have the "western diet". Now Finland, north and west of Germany, does surprise me at 67% overweight and obese. On this map you can also see cholesterol levels and tobacco use.

WHO obesity and overweight maps.

CDC: 2014, 28.9 percent of Americans who are obese, average for US, and by state. You can also see other indictors like overweight (child or adult), and older years.

CDC: Obese people have higher medical costs as a group.

Not everyone who has a high BMI is unhealthy. These include body builders, football players (who tend to be large) and people who get regular exercise. There is correlation that overweight people are unhealthy, because many of them rarely exercise. That does not mean all overweight people are unhealthy.