For those on antibioticsOptiBac Probiotics For those on antibiotics contains two high quality strains of natural bacteria, Lactobacillus rhamnosus Rosell-11 and Lactobacillus acidophilus Rosell-52. These two strains are amongst the most researched strains of the Lactobacilli family of bacteria. This supplement is often known as 'Lacidofil' in Poland and in other areas of Europe; Lacidofil contains these two exact strains of bacteria, usually at the same strength (4 billion live microorganisms per capsule).

Clinical Research on 'For those on antibiotics' alongside antibiotics

31 clinical trials have been carried out on 'For those on antibiotics', and the majority of these tested the supplement alongside antibiotics, in a number of cases the probiotics were administered at the exact same time as the antibiotics. These clinical trials on 'For those on antibiotics' demonstrate the ability of Lactobacillus rhamnosus Rosell-11 and Lactobacillus acidophilus Rosell-52 to survive to reach the gut alive, even when taken alongside, and at the same time as, antibiotics. Survival has been demonstrated in some cases by the discovery of viable levels of Lactobacilli in stool samples, and in other cases by significant gastrointestinal changes in the probiotic and antibiotic group as opposed to the antibiotic group alone. Some of the trials are listed below and available to view as PDF files; these are intended for professional use only.

'For those on antibiotics' has been tested alongside a wide variety of antibiotics, including but not limited to penicillin, amoxicillin, cephalosporins and fluroquinolones. The leading microbiological authority, the Institut Rosell, has also completed extensive safety tests on this supplement, such as demonstrating a lack of interference with antibiotics, as well as the inability of the bacteria to transfer antibiotic resistance genes. Furthermore Lactobacillus acidophilus Rosell-52 and Lactobacillus rhamnosus Rosell-11 are listed on EFSA's Qualified Presumption of Safety (QPS) list.

To our knowledge, no other company in the UK has this amount of scientific research on their probiotic strains when taken alongside antibiotic therapy.

Human clinical trials on OptiBac Probiotics 'For those on antibiotics'

Evans, M. et al (2016), Effectiveness of Lactobacillus helveticus and Lactobacillus rhamnosus for the management of antibiotic-associated diarrhoea in healthy adults: a randomised, double-blind, placebo-controlled trial, British Journal of Nutrition, 2016 Jul;116(1):94-103. doi: 10.1017/S0007114516001665. Epub 2016 May 12.

Evans summary:

In this latest ‘gold standard’ randomised double-blind, placebo-controlled clinical trial using 146 healthy adults, Lacidofil ('For those on antibiotics' probiotics: Lactobacillus rhamnosus Rosell-11, Lactobacillus acidophilus Rosell-52) was shown to reduce the incidence and duration of AAD by around 24 hours. The subjects were all given a broad spectrum antibiotic treatment (amoxicillin-clavulanic acid) for one week. Alongside this medication, and for one week afterwards, some of the participants were given the Lacidofil probiotic formula, whilst others were given a placebo. The results indicated that those given the probiotic suffered AAD symptoms for a significantly shorter period of time than those in the placebo group; this is the first study to use healthy adults as subjects and show a clinical benefit.


Aryayev M & Kononenko N (2009) Prevention of antibiotic-associated diarrhoea in patients with cystic fibrosis. [Odessa Medical Journal] 4 114 78

Aryayev summary: In a trial of 36 children taking antibiotics, 'For those on antibiotics' was again found to reduce side effects. Only 5.5% of those who took 'For those on antibiotics' developed antibiotic-associated diarrhoea, whereas 28.9% of those who only took antibiotics suffered with AAD. On the basis of these results the trial statisticians calculated the risk of developing AAD to be 80% less likely if taking 'For those on antibiotics'.



Babak O (2007) The use of Lacidofil in treatment of duodenal peptic ulcers associated with H. pylori. [News of Pharmacy and Medicine] 5 24-25

Babak summary: 'For those on antibiotics' has been shown in numerous clinical trials to be especially suitable to take alongside standard treatment for Helicobacter pylori (triple therapy: 2 antibiotics and 1 antacid). In these trials (Babak, 2007, Gnaytenko, 2009, Vdovychenko, 2008, Ziemniak, 2006) not only have the side effects from the antibiotics decreased but also the success rate of the treatment has improved with the addition of 'For those on antibiotics'. This is a very positive finding, especially since H. pylori can often be resilient to standard treatment.

Bielanski W, Ziemniak W, Plonka M, Dobrzanska M, Kaminska A & Konturek S (2002) Improvement of anti-Helicobacter pylori therapy by the use of commercially available probiotics. Gut 51 Suppl 11 A98

Chayka V, Dolgoshapko O, Babich T, Govorukha I (2006) Prevention of disbacteriosis in pregnant and women recently confined with surgical delivery. News of Medicine and Pharmacy 19 14-15

Gnaytenko O, Lychkovska O, Kulachkovska Y & Semen V (2009) Antibiotic-associated diarrhoea as a complication of antihelicobacter therapy in children. Practical Medicine 5 76-83

Ivanko O & Radutnaya E (2005) Lactobacillus acidophilus reduces frequency of diarrhoea caused by toxins Clostridium difficile A+B in children treated by antibiotics. Zaporozhye Medical Periodical 2 21-23


Ivanko summary: In a trial conducted in 2005, 57 patients who had been prescribed antibiotics were split into two groups - one group received 'For those on antibiotics' and the other group acted as a control. Over a third of the patients in the control group (36.7%) went on to develop antibiotic-associated diarrhoea (AAD), whereas only a few patients in the probiotic group suffered with AAD (7.4%).



Liskovich, V. et al. (2010) Efficiency of Lacidofil-WM for prevention of vaginal dysbiosis and antibiotics-associated diarrhoea in puerperas after caesarean operation. [Health] 1 63-66

Marushko Y & Shef G (2007) Current status of antibiotics-associated bowel disorders issue in children. Perinatology & Paediatrics 4 65-68

Maydannik V, Haytovich M, Sosnovska T & Kyrychenko I (2008) Prevention and treatment of antibiotic-associated diarrhoea. Paediatrics, Obstetrics & Gynaecology 1 63-65

Maydannik V, Khaytovich N, Boyarskaya L, Gnateyko O, Kaladze N, Senatorova A & Yulish E (2010) Efficiency and safety of Lacidofil in children with antibiotic-associated diarrhoea caused by Clostridium difficile. Pediatrics, Obstetrics & Gynaecology 3 53-57

Patsera M, Ivanko O, Shalmin A & Chernyshov L (2010) Using probiotic strains Lactobacillus acidophilus R0052 and Lactobacillus rhamnosus R0011 during pulmonary tuberculosis in children, complicated by antibiotic-associated Clostridium difficile intestinal infection. Zaporozhye Medical Journal 12 30-33

Plewinska E, Planeta-Malecka I, Bak-Ramaniszyn L, Czkwianianc E & Malecka-Panas E (2006) Probiotics in the treatment of Helicobacter pylori infection in children. Gastroenterolgia Polska 13 4 315-319

Song H, Kim J, Jung S, Kim S, Park H, Jeong Y, Hong S, Cheon J, Kim W, Kim H, Ye B, Yang S, Kim S, Shin S, Kim H, Sung J & Kim E (2010) Effect of probiotic Lactobacillus (Lacidofil® Cap) for the prevention of antibiotic-associated diarrhoea: a prospective, randomised double-blind multicenter study. Journal of Korean Medical Science 25 1784-1791

Song summary: In a larger trial conducted in 2009 involving 214 adults who had been prescribed antibiotics for chest infections, by taking 'For those on antibiotics' alongside the antibiotics, the risk of suffering with upset bowels was significantly reduced, compared to those who took placebo.

Tlaskal P, Michkova E, Klayarova H, Jerabkova L, Nevoral J, Balackova J, Tejnecka J, Valtrova V, Simandlova M & Kejvalova L (1995) Lactobacillus acidophilus in the treatment of children with gastrointestinal illnesses. Cesko-Slovenská Pediatrie 51 615-619

Vdovychenko V, Demidov A & Bidyuk O (2008) Effectiveness of quadra therapy probiotics in patients with duodenal ulcers. [Current Gastroenterology] 43 90-92

Wasowska-Krolikoeska K, Godzisz J, Kowalska E, Kwnatowski M, Toporpwska-Kowalska E (1997) Clinical assessment of L. acidophilus. Report for Institut Rosell Inc.

Wojoik Z, Chaber A & Dabrowski B (1996) Clinical trials of L. acidophilus. Report for Institut Rosell Inc.

Ziemniak, W. (2006). Efficacy of Helicobacter Pylori eradication taking into account its resistance to antibiotics. Journal of Physiology and Pharmacology 57 123-141.

Firmesse, O. et al (2005). Quantification after transit in human digestive tract of For those on anti biotics (Lactobacillus Rhamnosus Rosell 11 & Lactobacillus Acidophilus Rosell 52) consumed in a food supplement. National Institute of Agronomic Research. Presented at Rome Conference on probiotics.

More research on probiotics and antibiotics

The research below refers to scientific research on the same (or similar) species and families as those probiotics found in 'For those on antibiotics'. For finished product clinical trials on OptiBac Probiotics 'For those on antibiotics' please see the clinical trials listed in the sections above.

Probiotics prevent antibiotic-associated diarrhoea - A comprehensive report published in the American Family Physician in 2008 found probiotics to be effective in avoiding diarrhoea caused by antibiotics, as well as diarrhoea caused by gastrointestinal viral or bacterial infections. After reviewing 7 high-quality studies, this report stated that up to 1 in 5 people on antibiotics stop taking their full course of antibiotic therapy because they contract diarrhoea. Dr Benjamin Kligler, medical professor at the Albert Einstein College of Medicine where the report was carried out, assured that probiotics should be prescribed with antibiotics, regretting that “the average doctor is not doing this, and patients often know more about probiotics than their physicians.”

(NB: See also scientific research on For every day EXTRA Strength, which has also been successfully trialled to minimise disturbance of gut flora in those taking antibiotics.)

D’Souza, A. L. et al (2002) Probiotics in prevention of antibiotic associated diarrhoea: meta-analysis. British Medical Journal. Vol. 324 pp. 1362 – 1368

Jirapinyo, P. et al. (2002) Prevention of antibiotic-associated diarrhoea in infants by probiotics. J Med Assoc Thai 2002; 85 (Suppl 2): S739-S42.

Dr Benes, Z. et al. (2006) Lacidofil (Lactobacillus Rosell 52 & Lactobacillus Rosell 11) alleviates symptoms of IBS. Nutrafoods, Vol. 5 pp. 20 -27

Kocian, J. (1996). Further Possibilities in the Treatment of Lactose Intolerance: Lactobacilli. Prakticky Lekar (General Practitioner). Vol. 74. pp. 212 – 214

Vanderhoof, J.A. et al. (1999) Lactobacillus rhamnosus (GG) in the prevention of antibiotic-associated diarrhea in children. J Pediatrics 1999; 135: 564-8.

Arvola, T. et al. (1999) Prophylactic Lactobacillus rhamnosus (GG) reduces antibiotic-associated diarrhea in children with respiratory infections: a randomized study. Pediatrics 1999; 104(5): e64.

Wallace, T. D. et al (2003). 'Interactions of Lactic Acid Bacteria with Human Intestinal Epithelial Cells: Effects on Cytokine Production'. Journal of Food Protection. Vol. 66 Iss. 3 pp. 466 – 472

Chayka, V.K. et al (2006) Prevention of disbacteriosis in pregnant and women confined with surgical delivery. News of Medicine and Pharmacy. 19. 14-15

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