This study aimed to develop low-fat acerola ice creams enriched with partially hydrolyzed guar gum (PHGG) at concentrations of 6% and 12% and supplemented with Lacticaseibacillus rhamnosus GG. Three formulations were prepared by partially or totally replacing fat with PHGG. After preparation, the ice creams were stored at −18 °C and evaluated over 180 days. Physicochemical analyses showed no differences in pH, acidity, moisture, or ash content among the samples. However, soluble solids and fat content varied depending on the PHGG level. The melting rate remained stable, while overrun increased proportionally with PHGG incorporation. Rheologically, PHGG addition significantly enhanced consistency. Microbiological analyses confirmed that all samples complied with safety standards. The ice creams exhibited symbiotic potential, maintaining L. rhamnosus GG viability > 8 log CFU/g for up to 180 days. In simulated gastrointestinal resistance tests, probiotic survival increased with PHGG concentration. After one day, counts during the enteric phase were 3.87, 6.20, and 6.08 log CFU/g for 0%, 6%, and 12% PHGG, respectively. After 180 days, the counts were 1.98, 4.41, and 3.25 log CFU/g, with corresponding survival rates of 47%, 84%, and 78% after one day, and 36%, 53%, and 42% after 180 days. Sensory analysis with 121 untrained panelists revealed no significant differences in aroma and taste. However, samples with higher fat content were better accepted in terms of appearance, texture, and purchase intent. Overall, partial fat replacement with PHGG proved effective in reducing fat while maintaining quality and enhancing probiotic stability, supporting its potential for functional low-fat foods.