Featured Research

from universities, journals, and other organizations

Intestinal enzyme maintains microbial balance: Study shows how

Date:
May 9, 2014
Source:
Massachusetts General Hospital
Summary:
The mechanism by which an enzyme produced in the intestinal lining helps to maintain a healthy population of gastrointestinal microbes has been identified by researchers. The research team describes finding that intestinal alkaline phosphatase promotes the growth of beneficial bacteria by blocking the growth-inhibiting action of adenosine triphosphate -- an action first described in this paper -- within the intestine.

Massachusetts General Hospital (MGH) investigators have identified the mechanism by which an enzyme produced in the intestinal lining helps to maintain a healthy population of gastrointestinal microbes. In their report in American Journal of Physiology -- Gastrointestinal and Liver Physiology, the research team describes finding that intestinal alkaline phosphatase (IAP) promotes the growth of beneficial bacteria by blocking the growth-inhibiting action of adenosine triphosphate (ATP) -- an action first described in this paper -- within the intestine.

"We found that ATP is a natural inhibitor of bacteria in our intestines and that IAP promotes the growth of 'good' bacteria by blocking ATP," says Richard Hodin, MD, of the MGH Department of Surgery, senior author of the report which has been released online. "By helping to keep these healthy bacteria happy, IAP protects us against dangerous pathogens that can get the upper hand when the balance is disrupted."

The beneficial bacteria and other microbes that normally populate the human digestive system contribute to the digestive process and also prevent the proliferation of any disease-causing bacteria that may be present. A drop in the number of beneficial species -- which may be caused by antibiotic treatment, poor nutrition or other health conditions -- can allow the population of harmful bacteria to rise, contributing to serious medical problems including chronic diarrhea from pathogenic species such as C. difficile, inflammatory bowel disease, and metabolic syndrome.

Previous research by Hodin's team found that IAP keeps pathogenic bacteria in the gastrointestinal tract from passing through the intestinal wall, and a 2010 study in mice revealed that the enzyme plays an important role in maintaining levels of beneficial bacteria, including restoring levels reduced by antibiotic treatment. However, that study also showed that IAP does not directly promote bacterial growth, leaving exactly how the enzyme helps maintain the microbial population an open question that the current study was designed to investigate.

A series of experiments first confirmed that mice lacking intestinal IAP had significant reductions in populations of several important bacterial species. Hypothesizing that IAP may act by blocking a growth-inhibiting activity of one of its target molecules, the researchers tested how well bacteria in stool samples would grow in the presence of four known IAP targets. Among the tested targets, only ATP significantly reduced bacterial growth; and ATP's inhibitory effects were reversed by application of IAP. Best known as the primary energy supply within cells, ATP also acts as a signaling molecule both inside and outside of cells, and this study is the first to identify such an activity for ATP within the gastrointestinal system.

Experiments in living mice revealed that IAP knockout animals had 10 times the normal level of ATP within their intestines and that fasting animals, in which IAP levels would be expected to drop, also had elevated intestinal ATP. Adding ATP to the intestines of mice in which IAP activity had been inhibited reduced levels of beneficial E.coli bacteria in the animals' digestive systems. Altogether the results show that ATP inhibits the growth of intestinal bacteria in mice and that IAP's growth-promoting effects result from the enzyme's inactivation of ATP and possibly of related molecules.

"Now we need to find out whether IAP also promotes the growth of beneficial intestinal bacteria in humans," says Hodin, who is a professor of Surgery at Harvard Medical School. "If it does, IAP-based therapies could offer a simple and safe approach to treating the millions of patients who suffer serious health problems caused by disruptions to intestinal microbial balance."


Story Source:

The above story is based on materials provided by Massachusetts General Hospital. Note: Materials may be edited for content and length.


Journal Reference:

  1. M. S. Malo, O. Moaven, N. Muhammad, B. Biswas, S. N. Alam, K. P. Economopoulos, S. S. Gul, S. R. Hamarneh, N. S. Malo, A. Teshager, M. M. R. Mohamed, Q. Tao, S. Narisawa, J. L. Millan, E. L. Hohmann, H. S. Warren, S. C. Robson, R. A. Hodin. Intestinal alkaline phosphatase promotes gut bacterial growth by reducing the concentration of luminal nucleotide triphosphates. AJP: Gastrointestinal and Liver Physiology, 2014; DOI: 10.1152/ajpgi.00357.2013

Cite This Page:

Massachusetts General Hospital. "Intestinal enzyme maintains microbial balance: Study shows how." ScienceDaily. ScienceDaily, 9 May 2014. <www.sciencedaily.com/releases/2014/05/140509130046.htm>.
Massachusetts General Hospital. (2014, May 9). Intestinal enzyme maintains microbial balance: Study shows how. ScienceDaily. Retrieved September 2, 2014 from www.sciencedaily.com/releases/2014/05/140509130046.htm
Massachusetts General Hospital. "Intestinal enzyme maintains microbial balance: Study shows how." ScienceDaily. www.sciencedaily.com/releases/2014/05/140509130046.htm (accessed September 2, 2014).

Share This




More Plants & Animals News

Tuesday, September 2, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

We've Got Mites Living In Our Faces And So Do You

We've Got Mites Living In Our Faces And So Do You

Newsy (Aug. 30, 2014) A new study suggests 100 percent of adult humans (those over 18 years of age) have Demodex mites living in their faces. Video provided by Newsy
Powered by NewsLook.com
Washington Wildlife Center Goes Nuts Over Baby Squirrels

Washington Wildlife Center Goes Nuts Over Baby Squirrels

Reuters - US Online Video (Aug. 30, 2014) An animal rescue in Washington state receives an influx of orphaned squirrels, keeping workers busy as they nurse them back to health. Rough Cut (no reporter narration). Video provided by Reuters
Powered by NewsLook.com
Experimental Ebola Drug ZMapp Cures Lab Monkeys Of Disease

Experimental Ebola Drug ZMapp Cures Lab Monkeys Of Disease

Newsy (Aug. 29, 2014) In a new study, a promising experimental treatment for Ebola managed to cure a group of infected macaque monkeys. Video provided by Newsy
Powered by NewsLook.com
Killer Amoeba Found in Louisiana Water System

Killer Amoeba Found in Louisiana Water System

AP (Aug. 28, 2014) State health officials say testing has confirmed the presence of a killer amoeba in a water system serving three St. John the Baptist Parish towns. (Aug. 28) Video provided by AP
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:
from the past week

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile: iPhone Android Web
Follow: Facebook Twitter Google+
Subscribe: RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins