Probiotics in critical illness

Introduction

Critically ill patients are commonly treated with broadspectrum antibiotics. This brings about a major impact on the delicate microbiological balance in the gut, often causing diarrhoea and overgrowth of resistant pathogens and fungi.

Many potentially pathogenic bacteria adhere to enterocytes via a mannose-specific adhesin. This mechanism has also been found in Lactobacillus plantarum 299v (L p 299v) both in the jejunum in the rectum. It is when bacteria are adhered to the mucosa that they interact with the enterocytes, both in negative and positive fashions.

Given in fermented oatmeal soup to healthy subjects, L p 299v was detected even 11 days after termination of intake.

In patients with persisting Clostridium difficile infections this fermented oatmeal soup containing L p 299v has also been effective in normalising gutflora and function.

Objectives

The prime objective was to study if L p 299v could survive and colonise on the mucosa in the intestine of patients treated in an ICU. Stool consistency and frequency were among other parameters studied.

Method and materials

In a randomised prospective trial 8 patients received 200 ml daily for 3 days and then 100 ml of an oatmeal soup containing 10⁹ cfu/ml of L P 299v through out their stay in the ICU. Enteral nutrition as well as the oatmeal soup was started within 24 h after admission to the ICU. Control-patients (7) were treated in the same fashion except for the fermented oatmeal soup. The rectal mucosa was biopsied after admission and then twice a week. Biopsies were analysed blindly for bacterial content and species.

Results

Four of the control patients were colonised with L p 299v on admission, but at the second biopsy they were all negative. Of eight treated patients none had positive cultures for L p 299v on admission but from the second sample and through their ICU-stay three of them had the bacteria adhered to the mucosa confirmed by cultures from homogenised biopsies.

Bacterial analyses revealed a reduction of sulphite-reducing clostridia in the treatment group. In treated patients lactobacilli increased while they remained at the original level in controls.

Diarrhoea was less frequent in treated patients.

Discussion

The initially positive biopsies in four of the control patients were probably due to that these patients had ingested L p 299v through the commercial L p 299v-containing `Proviva', which is sold in almost all grocery-shops in southern Sweden. The use of antibiotics leads to a level of L p 299v below the limit of detection in those that were colonised from the beginning.

In the treatment group the L p 299v adhered to the mucosa in 3/8 patients although they as well were treated with antibiotics. It seems that repeated administration is essential if the bacteria should remain in sufficient numbers adhered to the mucosa. Our study shows that antibiotic treated patients in an ICU environment can benefit from probiotics. Less diarrhoea means less impact on the gutflora.

By the repeated administration of the oatmeal soup fermented with L p 299v it is concluded that the bacteria can adhere to the gut mucosa in antibiotic treated critically ill patients. Further studies with larger numbers of patients are needed to evaluate other effects.