Pro-Probiotics – Anti-Antibiotics

Stuttering title? No – just being trendy.

Bacteria had to compete with a standard antibiotic for the best treatment option of repeated urinary tract infections (UTI). Dutch researchers conducted a randomized placebo-controlled trial that involved 250 postmenopausal women (an age group at higher risk) with histories of at least three UTIs in the previous year. The women received either a standard dose of the antibiotic Trimethprim-Sulfamethoxazole once at night time or a standard dose of Lactobacillus rhamnosus and Lactobacillus reuteri twice daily.

During the next 12 months the mean numbers of UTIs were 2,9 in the antibiotic group and 3,3 in the Lactobacilli group, whereas in the previous year the mean had been 7 in both groups. The overall number of UTIs therefore was more than halved. The between-group-difference was minimal and statistically not significant and therefore both treatments would be judged as being equally effective.

The interesting point though was that bacterial resistance in the antibiotic group rose from 20 % (normal) to 80 % and after a year of treatment it had climbed to 100 %!  In other words: the antibiotics had no effect anymore! On top of this, the bacteria did not only develop resistance against this particular antibiotic, but also against Amoxicillin – a very different sort of antibiotic! No increase in resistance to any antibiotic was found in the Lactobacilli group (Arch Intern Med 2012 May 14; 172:7).

A naturally occurring bacterium was as effective as a standard antibiotic for UTIs without causing problematic and to-be-avoided bacterial resistance – quite something to think about!

I do wonder though about the ethical aspects of this study: 140 women were treated in a way, which caused them bacterial resistance to two very different and very frequently used antibiotics! Bacterial resistance is considered a major health problem nowadays and particularly in the Netherlands. Which ethic commission agreed to the study being prolonged for another 11 months, after it had become clear after the first month that resistance had risen from 20 to 80 %? Where was this study done – in remote Malaysia?

Anyhow – bacteria, those invisible buggers which can cause so much harm (meningitis, pneumonia, gastroenteritis, boils…) have kind hearted brothers and sisters which tend to live in great peace with our modest selves. Yes – very modest selves. Because from shortly after we are born, each of us lives with 10 times as many bacterial cells as human cells in our bodies.

The metabolism of human cells influences that of bacterial cells and vice versa. For that reason the collection of microbial genes has been called “the second human genome” or Microbiome. The Microbiome has been implicated as a cofactor in many human diseases such as obesity, inflammatory bowel disease, cancer, psoriasis, type 2 diabetes and asthma. Nowadays, relatively inexpensive genome sequencing fuels international efforts to study the Microbiome. The Human Microbiome Project has collected repeated samples from different body sites of healthy adults.

Along with roughly 20.000 human genes there are another 5 to 8 million (!) bacterial genes in the Microbiome. Different species dominate in each body niche and vary with body weight, ethnic background and geographical location (Nature 2012 Jun 14; 486:207).

These studies are opening a huge new field in biology and medicine and if they achieve to determine how the Microbiome affects normal human health or leads to disease it will be a fascinating view into nature’s kitchen.

20.000 as compared to 5 million – everybody is a minority! Nevertheless a very proud and demanding one! Normally quite full of him/herself.

Have we not seen that elsewhere as well?