Acute toxicity                                                                                                  

Short-term studies

Monkey
Prepubertal rhesus monkeys (2/sex/group) were dosed by oral gavage with Gellan Gum at levels of 0, 1, 2 or 3 g/kg/day for 28 days. There were no overt signs of toxicity reported.

Long-term/carcinogenicity studies

Mouse
Groups of 50 male and 50 female Swiss Crl mice were fed Gellan Gum admixed in the diet at 0, 1.0, 2.0 and 3.0% for 96 and 98 weeks for males and females, respectively.  All animals were examined twice daily for mortality and morbidity.  Physical examination for the presence of palpable masses was initiated on a weekly basis starting in week 26.  Bodyweights and food consumption were measured for 7-day periods on a weekly basis for the first 26 weeks of treatment and every 2 weeks thereafter.  There were no effects attributable to the feeding of Gellan Gum on either body weight gain or food consumption.  There were no neoplastic or non-neoplastic changes which were associated with the feeding of Gellan Gum.

Rat
Groups of 50 F1 generation Sprague-Dawley rats of each sex were exposed to Gellan Gum in uteroand continued on Gellan Gum diets for approximately 104 weeks.  The dietary levels of Gellan Gum were 0, 2.5, 3.8 and 5.0%. The authors concluded that in spite of the initial bodyweight deficit, the growth pattern for these treated groups was identical to that of the control.  In addition, this effect was not seen in either the females or any other species tested. There is no basis to suggest that the lower bodyweights, observed in the male rats, are indicative of toxicity. The authors concluded that under the
conditions of this bioassay, Gellan Gum was non-carcinogenic to Sprague- Dawley rats.

Dog
Diets containing 0, 3, 4.5 and 6% Gellan Gum were fed to groups of 5 beagle dogs per
sex for a period of 52 weeks. All animals survived treatment.  Food intake was higher in the treated groups compared to the controls.  There were no adverse effects associated with the feeding of GELLAN GUM to beagle dogs for a period of one year.

Reproduction studies
Groups of 26 male and 26 female CD (Sprague-Dawley) rats were administered Gellan Gum in their diets at doses of 0, 2.5, 3.8 or 5.0%.Males were treated for 70 days prior to mating and for three weeks after mating.  Females were treated for 14 days prior to mating and throughout mating, gestation and lactation. There was no treatment-related effect on mating or fertility index, conception rate, length of gestation, length of parturition, number of live pups, number of dead pups, post-implantation loss index, survival index on day 4, 7, 14 or 21 or lactation index for any of the generations.

Teratology studies
Gellan Gum was fed to groups of 25 pregnant female Sprague-Dawley rats at dietary levels of 0, 2.5, 3.8 or 5.0% during days 6-15 of gestation.  Gellan Gum had no fetotoxic or teratogenic effects on rats when ingested in the diet at levels up to 5.0%.

Observations in humans
Five female volunteers and five male volunteers, all normal in health and free from gastrointestinal disease, participated in the clinical study. Following a 7-day control period, each of the volunteers consumed the test substance at a daily dose level of 175 mg/kg for 7 days, then the dose was increased to 200 mg/kg/day for a further 16 days. The authors concluded that the ingestion of gellan gum at the given dose levels caused no adverse dietary nor physiological effects in any of the volunteers on the study. 
There were no allergenic nor other subjective untoward manifestations, reported by or observed in any of the human subjects.  The ingestion of gellan gum, at the stated daily intake levels, did not cause any adverse toxicological effects. 
However, gellan gum does act as a faecal bulking agent, increases faecal bile acid, decreases faecal neutral sterols, and decreases serum cholesterol.