Very high triglycerides. Could chewing bubble gum before fasting blood test affect this?

No. Very high triglycerides are a serious issue and rather than looking for outlandish explanation, work with your doctor to lower these. In general weight control, reduction in the intake of carbohydrates and saturated fats may help.
Yes. If the gum you chewed contained a lot of sugar, this could certainly have an impact on your triglycerides. In general, your cholesterol test should be done after an 8 - 12 hour fast. Best of luck!